Some people have started their Social Security and take a big penalty going back to work. There should be a law allowing to stop social security and resume it later..it would save the USG money.
Otherwise..and I know several..the seniors go to work in the black economy and don’t report their income. Things like child care and elder support. Working at seasonal cash employment etc.
It only hurts if you report that extra income. Become self employed - its really simple.