Hello there! So I've been trying to figure out a method how to lock my room's door. The problem is - it DOES have a lock, but there are too many keys that can open the door, which makes it pretty dumb and useless. I need a method to lock the door, even if it costs money. I can't have heavy installation on the door, it's a simple inside wooden door. I tried to run a search but I dont seem to find something useful, most systems require heavy installation. Help please Thank you!