I wonder if anyone can help me. Ron and I have separate bedrooms and I sometimes don't hear him if he gets up in the night. What I need is some kind of alarm to let me know when his bedroom door opens[I don't close it completely] I've been searching the internet in vain and can only find commercial ones. I've even considered hanging a windchime on the inside. It would probably be the cheapest option. Anybody there who has solved the problem???? Help please.