Here’s how to make a quick and dirty alarm system using stuff you might have around the house. It’s not a heavy duty item, but you could freak out teenagers returning after curfew, or discover that pantry raider! You could also use it for securing your perimeter while camping or in an urban disaster situation.
Fix it to a trip-wire, or a door handle. Using a beeper or a bulb you can make this handy alert in a couple of minutes.