DIY Basic Wireless Alarm System

Open the front door. Spray the front door edge and the front door's frame edge with household cleaning spray. Wipe the edges dry with paper towels.

Place the wireless alarm sensor plate against the bottom edge of the front door. Screw the plate into the door's edge with wood screws using a Phillips screwdriver.

Close the front door and lock it in the usual manner. Mark the position of the wireless alarm sensor plate where it meets the edge of the door frame with a grease pencil. Open the front door again.

Place the wireless alarm sensor receiver plate against the edge of the door frame where the grease pencil mark was made. Screw the plate into the edge of the door frame with wood screws using a Phillips screwdriver.

Open the battery compartment lid on the back of the wireless transmitter attached by wires to the wireless alarm sensor plate. Insert a compatible battery into the battery compartment and close the lid. Place the wireless transmitter against the side of the wall, next to the door frame.

Screw the transmitter to the wall next to the door frame with wood screws using the Phillips screwdriver. Turn the transmitter on if there is a power switch or button. If a power cord is attached to the transmitter, plug the cord into a wall outlet; an extension cord can be used between the transmitter and the wall outlet if the distance is greater than the transmitter's cord can reach.

Place the wireless alarm receiver on a night table or on a table in a room that is central to the house. Plug the receiver's power cord into a wall outlet and turn it on. An alarm will now sound from the receiver if the front door is opened after you've locked it.