Use your own car alarm as an add on to any house alarm you might have by parking your keys on the nightstand.
If you feel or hear someone in your house that shouldn’t belong there, hit the panic button on your remote. Most, not all, car alarm systems can be activated from anywhere in your house. It doesn’t matter if the car is in the driveway or the garage. Of course, you should try it first.
All it’s going to do is honk the horn and let somebody know that something is going on, but that horn will keep going until the battery dies or you turn it off.
While it’s certainly not a replacement for a home security system, it is simple, and could be effective in any number of situations. I think this is just a brilliant idea – and so simple!