he has white hair, he walks slow, he can't do a lot of activity, but he wants to work as an extra, audience work.
What is the best place/company he can join for him to work a few times a week?
it doesn't have to be everyday, he wants to have fun.
any advice will be helpful.

Aww, bless his heart. I saw an ad on Craigslist a few weeks ago for paid audience work. I also discovered http://www.standingroomonly.tv

Do you like standing room?
I heard they have incredibly long lines to pay people and that they are not generous, meaning, they say 8 hour day, then one works only 6 hours and one gets paid for only 5 1/2, while other companies would pay you for 8 hours whether you worked 8 hours or just 2.
Standing room, I heard overworks people for very little pay.

Surely Central Casting, Extras Casting, and Atmosphere have a need for seniors fitting his bill? It may not be a few times a week but still, it's something.

Awesome, thanks peanut