Just yesterday I had to stop into a senior assisted living building to drop off a delivery from my hardware store. I didn't think about it much until I was walking into the lobby. But, I had the idea to start a model railroad club for the residence of the place. I asked the receptionist if such a club existed there and she said no, "Maybe I should go teach boy scouts and cub scouts. These people here are here because they need Assistance". She told me they have a "Yarn Club" and a "Rosary Club"...huh? I was upset about what the lady said. They are people, they need activities to stay alive. They're not dead yet. I'm sure many of them were into trains of some form or another. Why not show them the joy and gratification you get from building your own world. With all the many facets of the hobby, I'm sure many of them would find some interest in the hobby to fulfill their needs and enjoyment. I'm going back to that place and drop off some old Model Railroad magazines I have, and try to talk to a few of the folks there in the dining room. I want to get a feel from THEM, not the receptionist, how they would like the idea.
Try to meet with the activities director. I'd do that before talking with the residents about it. I think it would be cool. My Mother and my MIL are in assisted living and I find it's hard to get them interested in the provided activities so maybe something new and different would be nice.
The places I'm familiar with don't have many men residents so the interest from the ladies may be more in the scenery.
Keep in mind the activities ususally have a low budget so don't expect much in the way of reimbursement of your expenses.