It's a bit early, but around October, keep an eye out for churches selling pumpkins as fundraisers. The pumpkins have to be turned regularly, or they rot on the bottom, and then they can't be sold. A 7 1/2 year old is just the right age to go out on a weekday after school and help turn pumpkins (he needs some adult help, though - some of them are heavy).
Also, some of the retirement communities and nursing homes around us will welcome children to come and sit in the common rooms and socialize with the residents. That could be working puzzles or playing board games or joining in song nights - even better if he can get some friends to come with him. Also for the nursing homes, and also a bit early, our scout group makes cards on holidays. Perhaps he could call a local nursing home and see, for example, how many residents are veterans, and make up some thank you cards to be delivered on Veterans' Day? That's a fun activity to do with friends, too.
Some of our local parks also have tree planting/park cleanup days. Your local Parks and Recreation Dept. might have some info about that on their website.
Also, call the Goodwill. If there is a Goodwill computer center near you, he might be able to help disassemble computers for recycling (this is dusty work, and he WILL need work gloves that fit). Again, he'll need adult help, but it's fun, and fascinating. I'll bet some of his friends will think it's fun to take things apart, too. (You'll have to sign a release - some of the parts inside are sharp - thus, the gloves.)