The following story was related to me a couple of years ago. I thought you might find it amusing, if not downright scary!
The owner of a small campsite wanted to rig the light in the washroom's toilet cubicle so that it would automatically come on when the door was shut and go off when it was opened.
Easy enough to arrange with a microswitch arrangement of some kind, but hey, that costs money!
The door and frame were wooden, and there was a nice two-part metal bolt there, so.....
Yep, you've guessed it. The guy ran one wire down the frame and secured it under the fixed plate and the other across the top of the door and down to the other part. Instant automatic light switch!