Rep. Richard Kelley (R-Fla.) claims to be the only member of Congress whose sanity has been certified medically.

The claim was made in times of Kelly's palmier obscurity, before his catapault ride to media stardom this week as a lead player in the FBI's videotaped tragicomedy of legislators purportedly lusting after cash.

Kelly is the congressman who, according to nicely placed official leaks stuffed his pockets with $25,000 in bribe money and then asked, as the tape machines recorded it all, if any bulges were showing.

He now is also the only one of the FBI's targets who admits he took the money; he claims he accepted it as part of his own one-man investigation of corruption, which the FBI, in effect, blew for him.

It has been some time since this town has heard assertions as spectacular as these. In fact, however, Kelly has been doing his own thing for years.

He is, for example, a former Florida circuit judge who was nearly impeached in 1963 on the grounds of irascible conduct and mental instability. Kelly hectored lawyers so mercilessly in his courtroom that the Florida House voted to impeach him. The state Senate dismissed the case.

In the course of a subsequent judicial inquiry, Kelly voluntarily took a sanity test and apparently passed with flying colors. He has alluded to that certification as a badge that no other member of Congress can wear.

Kelly, tall and always Florida-tanned is from Zephyrhills. It is a small community in the states' Fifth District, a crazy quilt that spreads from the Gulf of Mexico to the outskirts of Orlando in central Florida.

After studying law at Vanderbilt and the University of Florida, Kelly became Zephyrhills' city attorney. Between 1956 and 1959 he was assistant U.S. attorney for the southern district of Florida.

He was elected to his judgeship in 1960, running against a well - entrenched machine candidate, and he quickly began making waves. He put an end to traditional courtroom informalities and often spoke out on such topics as lawyers' sloppiness and the inhumaneness of prisons.

Kelly, 55, also is an elder of the Presbyterian Church in the United States. His fourth marriage, to a young woman who was on his congressional staff, set tongues wagging during his last reelection campaign.

Since his election in 1974 Kelly has come to be known as one of the House's free-spirits -- a reputation he has carefully cultivated, while at the same time building a record as a skinflint conservative and an enemy of budgetary fat.

Ironically, he has had financial problems of his own. Alimony and divorce expenses have eaten into his exchequer and last year he borrowed $10,500 from a bank to repay overspending his congressional office account. House finance officials will not divulgue figures or names, but say privately that such overspending is rare.

Often, as a member of the House Agriculture and Banking committees, Kelly is the odd man out, the lone "no" vote on otherwise easily passed issues.

Last spring, opposing a bandwagon effort to attach a gasohol amendment to a sugar support bill, Kelly lectured the Agriculture Committee.

"I have no objection to standing trail," he said. "If reason and logic are an offense in Congress, then maybe someone should be tried. And I may be the guilty party. If I offend you, so be it."

That was vintage Kelly, not unlike the audacious Richard Kelly who has become a front-page figure these past few days as a target of the FBI "sting" that went by the code name of ABSCAM.

His story, basically is that he took the $25,000 they laid before him because he sensed he was onto "a criminal conspiracy" of ominous dimension.

As a legislator, as a former judge, as a one-time prosecutor, Kelly knew he was being given "a unique opportunity" to do what any upstanding citizen would do -- bust a gang and put evil to route. He laid out the story yesterday at a tumultuous press conference that carried all the flavor of theatre of the absurd.

Reporters who jammed the House Agriculture Committee chambers, where Kelly stood at a lectern and fielded questions for an hour, went for the thoat.

Do you know the definition of a bribe?

"I think it was a bride," Kelly said. "I didn't take the money with the intention of being engaged in a crime. "I wanted to know what these cats were up to."

Do you expect the American people to believe that?

"Yes, I do . . . It is not inconsistent for an honest man to begin an investigation."

What in the world were you going to do with the money?

"The money was a sort of device," Kelly said. "These are felons, lawyers, accountants -- thugs, mean people. They don't fall out of a Christmas tree. I wanted to understand the dimension of what I was dealing with."

Why did you keep on buying lunches?

"I wanted them to know I used the money. By simply having me followed, they could determine what I was spending." Would you take a lie detector test?

"Absolutely not. I don't trust them."

Can you prove your story?

"If I thought I had to depend on gusy like you, I'd go up in a puff of smoke. You guys haven't done me a favor since I've been in Washington. There's no way you can tell the whole truth."

Somebody wondered whether, if Kelly face trail as a result of the FBI "sting," he might plead insanity as a defense -- and interesting question for a man who has a certification of sanity.

"I hadn't thought about it," Kelly said. "But I'm not sure it would not be a good defense."