KCBS' "2 On The Town's" game shows episode went behind the scenes at Pyramid; even though it was done at Studio 33, the audience was that small...even for a very popular show!
$1,000,000 Chance of a Lifetime was like that as well; in one episode on YouTube, there was no sweetening during the first segment, and we got to hear the true audience applause. Either the person in charge was napping or forgot about it in post-production.
/Another reason for the "portions of the program not affecting the outcome of the game have been re-created or edited" disclaimer