In 1981, Kaufman made a couple of memorable appearances on Fridays, a variety show on ABC that was similar to SNL. Kaufman's first appearance on the show proved to be the most memorable one. During a sketch set in a restaurant, Kaufman broke character and refused to say his lines.

The other comedians were embarrassed by the position that Kaufman had put them in on a live television show. In response, Michael Richards walked off camera and returned with a set of cue cards and dumped them on the table in front of Kaufman. Andy responded by splashing Michael Richards with water. A stagehand stormed onto the stage, leading to a brawl on camera before the show finally cut away to commercial. The entire incident was apparently a gag conceived by Andy Kaufman, but how many people were in on the gag (if any) was never made clear.

Regardless, Kaufman appeared the following week in a videotaped apology to the home viewers. Later that year, Kaufman returned to host Fridays. At one point in the show, he invited gospel singer Kathie Sullivan on stage to sing a few gospel songs with him and announced that the two were engaged to be married and talked to the audience about his newfound faith in Jesus. It was of course entirely a hoax

(good ol' Wikipedia)