Is there something you can put on your phone so it hangs up when the caller hangs up?

I wish there were--hope someone can come up with one. The problem we have is Mom (who has dementia) is quick to answer the phone but doesn't know what to do with it once she's picked it up. She can't figure out how to hang up. So she's incommunicado until someone comes along and finds the phone off the hook.

Yes there is because amputees use such devices. Check with a VA (Veterans) office and they'll be able to put you on the right track.

google "phones for handicapped people" and you'll find some options. For example there are even voice-activated phones for paralyzed people. Sounds like you need the speaker to be really loud, too.

I do not understand your question -I do not think there is any other way but to hang it up yourself by pushing the off button or the old phones by hanging it up why do you need another way if the person forget to hang up their phone there is not much you can do about and if you do not want to talk anymore to that person you can just put the phone down and leave that plae.