Any retirees here who do volunteer work?

I am seriously thinking about retiring soon. I am feeling very burnt out doing computer programming.

I have saved a sufficient amount of money to live comfortably. The problem is that I live alone and would need to do something that I feel is meaningful and that would connect me with the outside world. I am not psychologically ready to move to a retirement community.

Have you or anybody you know been in a related situation? I would be particularly interested in hearing about retired educators, since I would be interested in doing math teaching if opportunities were available.