I don't mean as an actor - but as an extra or accidentally or maybe a contestant or some other way.
In the late 1980s I was a contestant on the quiz show 15 to 1.
I had a great time and I still have the recording. Only trouble is - the recording is on a betamax cassette.
I first went to the regional interviews where we actually played the game and William G Stewart was there to choose the contestants for the show.
I remember we were paid very good expenses and stayed in (what I thought at the time was) a very posh hotel where all drinks and food were free.
I was contestant number 1 and so got the first question to start the show off. William G Stewart was very nice and spoke to me for quite a while before it began.
I was knocked out in the second round after fielding about 25 questions. A woman got in the final 3 and she only was asked three questions