What began as a well-meaning campaign to fulfill the wishes of a terminally ill boy has turned out to be a nightmare spanning two continents with a bridge of postcards.

Tiny Spring Hill, 50 miles north of Tampa, has been bombarded with calls and cards for a local boy with cancer known as "David."But there is no such youngster here. The boy actually lives in England, and his name is Mario, not David. His cancer is in remission and he doesn't need, or want, any more cards or letters.

But that information came too late to Salt Lake City residents. Sheriff Pete Hayward said his office received a national police information broadcast Wednesday requesting that law enforcement officers and elected officials send Christmas cards to a boy dying of leukemia.

Copies of the broadcast were sent to the Utah media and each police division. The word was spread and cards started flowing. Copies of a similar story were also distributed among lawyers and court clerks at the federal building in Salt Lake.

The whole thing began in September 1987 when the 13-year-old critically ill English boy decided he wanted his name to appear in the Guinness Book of World Records for receiving more postcards than anyone else.

Now, a year later, Mario Morby's cancer is in remission. And even after making the 1989 edition of the record book, cards are still coming from millions of people worldwide who hear variations of the story.

"The cards took over our lives," Anna Morby, Mario's mother, said from their home in Steely, England. "Can you imagine opening your front door and seeing sacks and sacks of postcards? It's a nightmare."

Bags and bags of postcards keep coming, and the holiday season has brought it to a frenzy.

The Morbys had hoped to get 25,000 cards. They got 3 million.

A Spring Hill post office box, or sometimes a West Palm Beach number, wound up as the mailing address for the American end of the campaign.

Frances Keefe, founder of Florida Child's Wish Come True organization here, heard about it from a Florida woman who had visited England and heard about it from her mother.

Keefe is now pleading for the cards to stop.

"I have a sunken living room that has 37 boxes of mail in it," she said.

Aline Morin, a member of the Ladies Auxiliary of the Veterans of Foreign Wars Post 3588 in Lake Worth, heard about the campaign in a letter from Keefe's foundation in August. She took it on as a special project and offered her West Palm Beach address as a gathering place for cards.

"It's going from one person to another person to another person."