With fitting rooms at the clothing store, it sure would be nice to make some easy way to know if the room is occupied. Is something made? I know Kwikset has an "occupied" deadbolt, that has an outside signal when the bolt is thrown.
How about a door mat, with a weight sensor. If someone is standing on the pad, it blinks a LED, that can be seen from outside.
Or, a plastic piece, that the store employee can tip up when someone walks in, and falls down on its own when the door opens again.
This banging on the door to see if anyone screams, that's so old fashioned.
Is anything made, that I can offer to stores, and make some money installing such a system?