When I moved into my new apartment all I got were a bunch of child proof locks on all the cabinets that I had to disassemble. Why not leave a little time capsule for future tenants of your dwelling to discover? Here you can download a template to print out and affix to the inside of light switches in your home. Presumably the next time they replace the light switch they will discover your note. Do you think someone would discover these hidden notes or would a future electrician simply toss it aside without noticing?
Link
i did my part though. when i was a kid and we were moving, i went into the back of my closet and wrote/carved "help me" several times on the wall.