Cops may have seen it all and ladies of the night may have done it all, but Phil Fuller has heard it all. The sign outside his office reads "Allegheny Airlines Lost and Found." It might as well read: "The Abuse Starts Here."

"There is never a happy person who walks through that door," Fuller says. And hunhappy people tend to express themselves.

Their bags en route to Somewhere Else, people cast aspersions on Fuller's mother. Their wig cases crushed, people loudly threaten that their lawyers will soon be baking Allegheny Mince meat Pie.

A luggageless customer once declared, "It's either my bag or your neck." For emphasis, he picked up a copy of the Official Airline Guide - a schedule book as thick as most Yellow Pages - and ripped it in half.

But Phil Fuller still has a neck and, almost incredibly, a sense of humor. Despite more than eight years as Allegheny's National Airport lost-and-found chief, Fuller, 36, says he is still "dedicated to helping people," still "able to smile sincerely." Moreover, he says he is "still capable of being suprised."

It would be hard to be anything else if one were handling a lost bag one day and felt it vibrating.

I thought it might be me," Fuller said. "So I got the guy from American over here. 'You feel it vibrating?' I asked him. 'Sure do,' he said."

So Fuller called the police. The bomb squad opened the bag with excruciating care. There, pumping idly up and down, was an electric back-scratcher gone berserk.

Or what about the time Fuller had to open an unclaimed bag to see if something inside could help him identify the owner? There were no letters or pill bottles or business cards. But there was a large, live, hungry snake.

Nor could Fuller's mouth have dropped much father open than the day he had to inspect a duffel bag belonging to a serviceman just back from Vietnam.In he reached. A few days later, his arm was covered with ring-worms.

But the amazement is sometimes the customer's.Like most airlines, Allegheny will go to whatever lengths it must to see that person and luggage are reunited. Sometimes the lengths stretch the imagination - and the budget.

There was the time, for example, that a man from the South flew up to a remote region of Canada to do some fishing. He flew the Washington-Toronto leg of his trip on Allegheny. But somehow, his bag never got north of Alexandria.

Enter Fuller. He got the bag on the next flight to Toronto, then arranged for a seaplane there to complete the bag's journey. It cost $300, but the astounded fisherman was reunited with his suitcase before nightfall.

Sometimes Fuller has to be a mindreader as well as a detail man.

One recent day, a Kodak executive from Rochester, N.Y., was in Fuller's office, greatly distraught that his bag was not in his hand. Fuller asked him for the luggage claim check. The man did not have one, but he swore that he had checked his bag at the Rochester airport.

"Could you have left it in your car?" Fuller asked. The light of recognition in the man's eyes went on like a Kodak flashbulb.

Up to Rochester on the next flight went the man's car keys. Out to the parking lot went an Allegheny agent. In the trunk was the bag. It, and the clean shirt it contained, were in Washington in time for Mr. Kodak's business meeting the next morning.

In fact, most of Phil Fuller's trials and tribulations end that way. "We almost never lose a bag," he said. "I'd say 99.8 percent of what we handle gets to the owner, usually within eight hours."

Fuller's talents as a lockpicker are no longer much use, either. He used to have to break into many suitcases to see if something inside would help identify the owner. Now, a Federal Aviation Administration rule requires names and addresses on the outside of each piece of checked luggage.

That in turn has meant that most of Fuller's "business" is the items people leave in seatback pockets and coat closets.

A lot of it is money. Fuller estimates that $7,500 in cash has been turned into him in eight years, including one wallet with $1,600. He can't begin to count the cameras or the raincoats.

What was Fuller's all-time surprise? He voted for one lady whose bag didn't arrive at National with her. it contained $1,000 in cash and eight diamond rings. For Fuller, it was routine to see that the bag made the next flight. But the lady was so overcome at getting her valuables back that she fainted at Fuller's feet.

Helpful as he is, and thanked profusely as he often is, Fuller cannot resist the urge to play cop sometimes. It's just that he never seems to have Kojak's instincts.

One day, an unclaimed bag sprang open in his office. Fuller peeked. "There were six bags of white powder and about a million empty capsules," he recalled.

Thinking he was about to put The Peruvian Connection out of business, Fuller phoned the FBI, the police and federal narcotics agents. "The owner turned out to be a chicken farmer," Fuller said. "The powder was chicken hormones."

Another time, Fuller though he had a marijuana smuggler dead to rights. But the mounds of leaves in his suitcase turned out to be breakfast tea, not pot. "All I could do was shrug," he says.

The all-time cruelest episode? Fuller remembered a lady who forgot that she was traveling with her pet cocker spaniel. She made her connecting flight to Louisville, but the dog didn't. It spend days in an Alexandria animal shelter before the woman remembered.

And the all-time wierdest? It had to be the man whose bag Fuller was trying to find. Suddenly, the man bent down, unscrewed his false leg, handed it to Fuller and asked Fuller to hold it for a while. "Said it was bothering him," Fuller recalled.

Much of his work would disappear, Fuller insisted, if people would get to the airport half an hour before flight time and rip old baggage tags off their luggage. But even lost-and-found agents who know the ropes get confounded sometimes.

Phil Fuller went to Puerto Rico on vacation a couple of years ago. "Mybags," he said, "haven't shown up yet."