DIY: Wireless Home Security System Deal

Place the motion sensor security alarm on a bookcase or table that faces the door that you want to protect -- for example, the front door. In a pinch, you can use a chair or even place the sensor on the floor.

Rotate the motion sensor security alarm so that the sensor on the front faces the door. Plug the motion sensor security alarm's power cord into a wall outlet. If the motion sensor security alarm has a battery backup, open the battery compartment lid, insert a battery or batteries -- depending on the make -- and then close the lid.

Press the power button or slide the selector switch on the motion sensor security alarm to "On" -- the exact button or switch will depend on the make of the alarm.

Adjust the sensitivity knob or selector switch to midway between the two extreme settings.

Rotate the alarm volume knob or slide the volume selector switch (depending on the make of the alarm) so that it's at the highest setting possible -- this will guarantee that the alarm will be as loud as it can be when there is an intruder.

Toss a pillow over the sensor so that it strikes the bottom edge of the door or falls in front of the door, no more than a few inches away from it. The alarm horn should sound. Retrieve the pillow. Press the "Reset" button on the motion sensor to stop the horn and reset the alarm.