PUT JIM Carrey in front of the camera. Make him read the Yellow Pages. Tell him to pick his teeth, play with a yo-yo, do weird routines with bongos. Anything. The result will always be funny.

Which makes him the perfect candidate to play Andy Kaufman, the widely misunderstood funny man who made a short-lived career out of trying not to be funny, and who would do things like, well, weird routines with bongos.

In "Man on the Moon," Milos Forman's biopic about the late comedian, Carrey replicates Kaufman with uncanny precision. The best scene of all is a comic beat-for-beat reenactment of Kaufman's "Mighty Mouse" sketch for the "Saturday Night Live" TV show.

As Kaufman, Carrey comes onto the stage, his eyes bulging with what seems to be childish shyness. The audience tension is delicious, and you can see immediately the kind of mischief Kaufman got up to: playing with -- and destroying -- expectations.

Before the hushed studio audience, he puts on a scratchy record, which plays the "Mighty Mouse" theme. As it plays, Kaufman stands stiffly next to the primitive record player, eyes larger than watermelons, waiting for his one cue: the line in the song that goes, "Here I come to save the day!"

When it comes, he lip-synchs the line, arm raised, then goes back to his rigid, wordless stance.

"You're insane," says George Shapiro (Danny DeVito), the man who is about to become his agent. "But you might also be brilliant."

Director Forman and his scriptwriters, Scott Alexander and Larry Karaszewski, would like us to believe in Kaufman's brilliance and genius. Their evidence: Carrey's fabulous Kaufman act.

But what was Kaufman's true significance? And was he a genius or a moron? I couldn't tell from watching this. Carrey's the charismatic engine to this train, but it's clear he's pulling the conceptual equivalent of mediocre freight.

The story covers Kaufman's nightclub beginnings as an Elvis impersonator, which is when Shapiro first spots Kaufman's potential; his unhappy years playing the Latvian character Latka on the "Taxi" series; his much-publicized wrestling bouts with women, during which he meets his true love, Lynne Margulies (Courtney Love); his famous performance at Carnegie Hall (when he invited the entire audience out for milk and cookies afterward); and his love-hate relationship with a fictitious character called Tony Clifton.

Tony Clifton's existence was a running gag hatched between Kaufman and his best friend/collaborator, Bob Zmuda (played by Paul Giamatti). Clifton, a longhaired, mustachioed boor with dark glasses, was a gone-to-seed Vegas entertainer who'd routinely insult his audiences and seemed to have a never-ending gripe against Kaufman. Kaufman and Zmuda took turns playing Clifton, just to keep people guessing about his true identity. And on one occasion, a belligerent Clifton crashed the "Taxi" set, cursing at the apparently surprised Kaufman. Hey, it was funny to them.

Although there's no question we leave the movie with a new affection for Andy Kaufman, this is not the legendary endorsement the moviemakers had in mind. But all credit to Carrey, whose one-man performance is almost enough to redeem the movie. I said almost.

MAN ON THE MOON (R, 118 minutes) -- Contains sexual scenes, nudity and obscenity. Area theaters.