How to help my grandfather?

Hello, this is my first time honestly using reddit. Not sure how to really go about this type of thing. My grandpa is 76 years old. He retired about 7 years ago. He was an electrician his entire life and honestly looked forward to it each and everyday. It was apart of his identity. He loved my grandma. She died unexpectedly 3 years into his retirement. They have been together since they were 14 years old. He spent his entire life revolving around my grandma, doing what she says, almost like she was his little drill sergeant but he loved that about her. Now he doesn’t know what to do in his spare time and ends up sitting on the couch all day and drinks. He had a stroke and we got him to stop smoking and drinking.

I guess my question is, how can i find an enjoyable hobby for an elderly person? He has become so content with not doing anything besides watch tv, but i feel like that has caused a lot more harm in his mental and physical health. He has problems walking now and has stopped driving cars, and he can barely stand. Yes it comes with age, but him sitting on the couch doesn’t help. I want some advice on what i could do to be more involved in his life. I do spend a lot of time with him, watching with him. But what is something i could do that can help retain his mental? I tried puzzles. He hated it. Also tried to do some light carpeting and painting but he didn’t have the patience and often got frustrated.

Help is appreciated