Solder the parts according to the schematic diagram then put it in the box. Make sure that the parts are properly secured. By the way, we just used a junction box instead of a project box because we don't have one.. You can use any box as long as the parts fit in.
Step 4: Test it.
As you noticed, the buzzer rings continuously. But if you put a magnet, the ringing sound will stop. To use this, attach a small rope to the magnet and the other side to the door. If anyone opens the door, the alarm will ring. :)