Some security guards spend their shifts dealing with everybody who walks through the door. Bill Conway deals with those who literally walk through the door.

Working the graveyard shift at the Salt Lake City-County Building, he claims to have seen more than his share of spirits, blinking lights and other unexplained phenomena.

No, he says with a grin, this does not include Salt Lake City Mayor Rocky Anderson.

"The mayor has been in a few times late at night, but there really aren't many people who come in after midnight," says Bill, 24, who has worked the night shift in the historic building for almost three years. "It's quiet and it's dark — some people tell me it would give them the creeps to work here alone at night. But I love it. This place has such a history — you can feel the imprints people have left in the building."

Bill has seen a few imprints as well. Hoping to share a few of his ghostly discoveries, he recently invited me to join him for a Free Lunch chat while conducting his rounds in city hall's darkened back rooms and hallways. "The entire building is allegedly haunted," says Bill. "Two children are said to have been killed when an elevator shaft collapsed during construction, and sometimes, on the fourth floor, you can hear laughter. Their mother is also said to be haunting the building, but I haven't seen her yet.

"Some people have worked here their entire lives and never seen a thing," adds Bill. Then, there are others, he says, "people like me."

Climbing the steps to the third floor, he pulls out his cell phone to show some pictures he's snapped while patrolling the building late at night.

The first photo shows a white "angel-like" figure hovering near the planning and zoning offices on the fourth floor.

"It was completely dark and I came around the corner and saw this image," says Bill. "It was a little startling, but I was open to the experience. I find it all fascinating."

A second snapshot is even more eerie, showing a clear image of a long-bearded man with his arms folded across his chest.

"It's said that an old judge haunts the building — I believe this is him," says Bill. He reaches for his keys and unlocks a door to the "historical room" off the City Council chambers. "This is where I saw him," he says.

"He was standing next to the fireplace and I felt a chill in the room. That's how some people say you can detect a ghost's presence."

Thankfully, the room is toasty on this particular night. So is the tunnel under the City-County Building, where Bill says Salt Lake City ghost hunters have used EVP (Electronic Voice Phenomena) to pick up the voices of spirits.