An extremely inexpensive way to fool would-be intruders.

Perhaps the biggest obstacle to fitting a burglar alarm in the home is the prospect of all the disruption caused by wiring door and window contacts and running wires all over the house back to the control unit. This has probably led many people to adopt an ostrich like approach, convincing themselves that "it will never happen to me".

The device described here mimics a PIR sensor. With a cost of about $11 US dollars (excluding batteries.) and installation consisting of hammering a small nail into a plaster wall, a "sensor" can easily be placed in every room.