Not an actor, but more than just a crew member....
I just saw Nick Schillace on a Match Game rerun from 1980-ish. No, not Lorenzo Caccialanza....the "real" Nick Schillace, a make-up artist who was so beloved by the Knots cast and crew that they named an onscreen character after him. He was apparently working his way up at CBS at the time of this game show episode, stepping on set to powder Charles Nelson-Reilly's nose (and making a mess). In real life, Schillace is married to Lauren Koslow of Days of Our Lives.