Paranoia runs deep. Into prime time it will creep.

Actually, paranoia is already there in the television networks' fall lineups. And it's not exactly creeping anymore - it's rushing headlong into the breech.And we're not talking about the sort of paranoia that network programmers feel when, say, they're trying to devise a lineup of shows to compete with NBC's Thursday-night ratings juggernaut. We're talking about shows whose main theme is full-blown, nearly clinical distrust of institutions, government, and even aliens from outer space.

The current paragon of paranoia, Fox's "The X-Files," has spawned a host of programs that mimic that show's constant looking-over-our-shoulders attitude. If you've somehow managed to miss out on "X"-mania, the show deals with two FBI agents who not only seek to explain crimes that seem linked to the paranormal but are also bent on proving that certain elements in the government are covering up contact with aliens.

And we're not talking about aliens from south of the border, but aliens from somewhere beyond the solar system.

"They aren't just investigators of the paranormal," said "X-Files" creator and executive producer Chris Carter. "They are, together, passionately trying to uncover what looks like a giant conspiracy."

Ah, conspiracies. They play a big part in the current wave of shows that seem somewhat "X"-eroxed.

And it's not that the characters in these shows have delusions of persecution. They really are persecuted.

This fall's Television Paranoia Parade marches through four of the networks - as well as into syndicated programming. CBS has an hour. So does fledgling network UPN. Fox is adding a second hour to the one it already has in "The X-Files."

And NBC has turned over an entire evening's programming to the genre. That's right - it's Paranoid Saturday Night on NBC starting in September.

Here's what's in store for viewers:

- "EZ Streets," a CBS police drama, features a cop whose partner and someone else extremely close to him are murdered in the pilot episode. He's set up to look like a bad guy, made part of a special investigative unit, learns that lots of people aren't what they seem, and sets off to uncover a governmental/law enforcement conspiracy.

- "The Burning Zone" takes the medical paranoia of the movie "Outbreak" several steps further. It conjures up a team formed to combat outbreaks of deadly disease around the world. And, in the pilot, that team battles a virus with a collective conscience bent on subduing the entire human race.

(It's also no coincidence that UPN is making blatant references to "The X-Files" in its advertising campaign for "Zone.")

- That Fox's "Millennium" should feature paranoia should come as no shock. It's created and produced by Carter, the man who brought "The X-Files" to the network. In this one, a man with special abilities helps hunt down various serial killers who are somehow linked to the coming millennium. And, in the meantime, someone is after him and his family.

- NBC's Saturday lineup opens with perhaps the most paranoid show of all - "Dark Skies," described by one of its producers as "alternate historic conspiracy drama."

In this one, there are actually two simultaneous conspiracies to be paranoid about - the aliens and the dark forces within the government that know about them. And not only are aliens real and taking over our bodies, but they've also taken over our history. In the pilot episode, the assassination of JFK is linked to alien infiltration.

- "The Pretender" follows, and in this one the conspiracy is linked to a corporation that kidnaps genius children to use for their own purposes. When one of them - the title character - escapes some 30 years later, he sets out to do good in the world while being pursued by vengeful agents of that evil conglomerate.

- And winding up the evening is "Profiler," a show that has more than a bit in common with "Millennium." A woman with special abilities helps hunt down various serial killers. And the one serial killer she hasn't caught is coming after her.

- Two of syndication's most successful sci-fi series will continue to deal with underlying plots of paranoia and conspiracy. On "Star Trek: Deep Space Nine," the very existence of the Federation is threatened by the evil Dominion - and the shape-shifting Founders of the Dominion could be anyone, anywhere.

On "Babylon 5," not much of anyone turned out to be what they first appeared when the show debuted three seasons ago. And the forces of good are doing battle with the insidious, evil Shadows.

- The ranks of syndicated paranormal reality - or is that unreality? - programs will swell in the fall with the addition of "The Psi Factor" and "Strange Universe," both of which are promising, oddly enough, to tell us more about the unexplained. They're joining continuing shows like "Sightings," which willl also be seen on cable's USA Network in addition to syndication.

- Astoundingly enough, even David Hasselhoff is getting into the act. His "Baywatch" spinoff, "Baywatch Nights," is being remade into a series about the paranormal after an unsuccessful first season as a straight detective show.

"We drew from a trend that is popular these days - kind of creature-of-the-week," Hasselhoff said.

Not that "Nights" will be an exact clone of "X-Files," which is "much more cerebral than our show," according to Haselhoff. (Big surprise there, huh?)

If Carter is unhappy about the subtle and not-so-subtle imitations of his hit show, he's not showing it.

"I can speak to my own paranoia, which is great," he said with a laugh. "If my paranoia has inspired more paranoia, I think that I'm a happy man."

And Carter isn't exactly willing to take the credit for the current wave - he sees himself as someone who helped make surfing that wave popular again.

"Have I unleashed something? I don't know," he said. "If so, it's inadvertent. . . . I think I'm responsible, if anything, in a very small way for re-introducing the genre. It's a genre that's been along for a long time."

(Indeed, when "The X-Files" was first introduced, Carter openly admitted he was trying to re-create the ambience of the 1974-75 TV series "Kolchak: The Night Stalker.")

Bryce Zabel, the creator and an executive producer of "Dark Skies" - a program he openly admitted "is a paranoid Saturday-night show" - also points to sci-fi roots that go back well before "The X-Files" appeared on the scene.

"Let's make no mistake, sci-fi has been around for a good, long time. And alien invasions were kind of a staple of the '50s," Zabel said. "They reflected, at that time, more a fear of communism."

But the current wave of paranoid entertainment may reflect current fears. And may help explain their current popularity.

"As we entered into the '90s, I think they reflect more a paranoia about what our government is telling us and whether it's telling us the truth," he said.

And the characters in the show he created don't seem to be greatly more paranoid about such possibilities than Zabel himself. He not only believes that there are UFOs, but he believes the government has had one in its possession for nearly five decades.

"I think that there's a core truth to this Roswell, New Mexcio, event that happened in 1947," he said. "And I think over the course of time people have begun to believe that and realize that something happened there that they haven't been told the truth about. And that if that really happened in 1947, almost 50 years ago, and to this day you haven't heard about it, it means that somebody's been keeping an awfully big secret from you for an awful long time.

"It makes some of the things that we posit in `Dark Skies' not so crazy after all."

Mistrust of the government and its institutions is a recurring theme in the current crop of conspiracy dramas.

"There's a cynicism in this country. There's a cynicism that's become endemic," said Paul Haggis, the creator and executive producer of "EZ Streets." "And this (show) is about a cop . . . that has to deal with that corruption and find his way through. And try to find a piece of truth."

"EZ" marks a considerable change in direction for Haggis. His most recent television creation was the decidedly upbeat and optimistic "Due South," which featured a Canadian Mountie who was perhaps the most upstanding, friendly - darn near perfect - character on network TV in recent seasons.

"In my last show we took the opposite direction and said, `People really want to get back to a simple life.' I think that's still true," Haggis said. "But, I mean, if you ask anyone in the street - do they trust the government? Do they trust their political leaders? In Los Angeles, do they trust the cops on the street? You'll find two completely different answers depending on who you're talking to. So I think we're addressing that."

The producers of paranoia maintain that they're not putting anything on the television screen that isn't out there in real life. That their creations are a reflection of the world we live in.

Carter said his own interest in the aliens-among-us genre began when he came across the research of a Harvard psychology professor who discovered that there were a good number of people who not only believed in UFOs, but believed they had been abducted.

"I honestly can't say why people believe this," Carter said. "I think it has a lot to do with the global political climate, the lack of a clear enemy and a certain amount of navel-gazing as well.

"But I think it has to do with science generally. We're living in a world where advancements are taking quantum leaps and we don't quite know how to fathom those things. And it gives us a feeling that, in fact, we may not be in control. And I think that gives rise to certain fears about the dangers from without."

The purveyors of paranoia also postulate that the coming millennium may have something to do with the current appeal of shows like theirs. As a matter of fact, "Millennium" deals with that on an ongoing basis - as you might have guessed from the title.

"The idea that we are heading toward a significant date in history is a part of the show," Carter said. "But it's not that these guys believe that the world is coming to and end in the year 2000. They believe that, in fact, all this random violence we see these days . . . that there may be some order in the chaos."

Should the show last that long, "Dark Skies" is scheduled to reach its climax when its time line and real time reach the year 2000. And the show's creator thinks that viewers millennial fears may be feeding their appetite for such programming.

"If you look back, historically, when the clock turned on the last millennium people were filled with fears and hopes and dreams of all kinds," Zabel said. "And it made for a really rich stew of emotion at the time. And I think the same thing is happening as we approach the millennium."

(Of course, neither Carter nor Zabel seemed to realize that the year 2000 doesn't mark the new millennium - it's actually the year 2001.)

But, in television, nothing breeds imitation like success. And "The X-Files" has been very successful, particular among the 18-to-49-year-old viewers that are so prized by advertisers.

NBC Entertainment President Warren Littlefield's take on his paranoid lineup - which he, naturally, prefers to think of in terms of "suspense, action, excitement" - is that his network "has nothing to lose" in light of dismal Saturday-night ratings the past few seasons. But he sees the trend toward this type of show as a trend away from the formulas the networks have used to create shows for decades.

"I think as a broadcaster, you've got to be pretty nervous about going out there with a traditional franchise show unless it's exceptional. . . . So I think what you see is networks trying to say, `We've got to get out of that traditional drama franchise. We've got to do something that's a little different,' " Littlefield said.

"You say, `Let's go for a change-up. Let's go for a franchise that's not a traditional franchise, not unlike the kinds of things that audiences are flocking to this summer at the box office."

And, indeed, the success of "Independence Day" at the box office fuels industry speculation that this is the sort of entertainment Americans crave at the moment.

The only thing certain in television, however, is change. In just the past few years both comedies and dramas have been declared dead by industry insiders - only to be suddenly reborn when a hit comedy or a hit drama hit the airwaves.

And the current success of paranoid TV will ride the coattails of "The X-Files" and any other successes - until the tide turns against them as well.