High schools and community playhouses are always looking for volunteers to help with tht sort of thing.
I used to be part of an amateur dramatics group when I was younger. But I was on the stage, and looking at those off stage longingly. I imagine it's usually the other way round.
At the moment, I don't have time to even think about it really, but there is a local theatre just down the road from me, so I may have to pop in.