- 1
Open your smoke detector and look inside. There might be clips on the sides that you push in to open it. Your smoke detector should be the type that has a test button that protrudes through the lid to check the function periodically. - 2
Find the contact that makes the alarm sound when you push the test button. It should be located under the test button or directly beside the base of the test button. It is a small piece of metal. Notice the staple that the metal touches when pushed. This contact between two pieces of metal makes the alarm sound. - 3
Shove the ends of a folded piece of yarn under the metal piece so it cannot touch the metal staple. The loop of the yarn should be hanging out so you can tie your fish line to it. The two loose ends should be preventing the contact. - 4). Place the lid back onto the smoke detector. The loop of your yarn should be hanging out from the opening on the side where the lid doesn't quite meet the base.
- 5
Use a piece of duct tape to tape the test button down. This would normally make the smoke detector beep, however the yarn is preventing the contact. The image has regular duct tape so you can see it better, but you should use clear to make your door alarm less obvious. - 6
Use two screws to attach your smoke detector near the bedroom door. You will need to put it about half way up the wall instead of the ceiling, not far from the door knob. - 7
Make a loop with the fish line that you can easily put over the doorknob and remove when necessary. The image has yarn to make it easier to see. Attach the other end of the fish line to the loop of yarn hanging out from the smoke detector. The line shouldn't have any slack in it when the bedroom door is closed. - 8). Open the bedroom door. The fish line should pull the yarn out of the smoke detector. This allows the two pieces of metal to contact each other. The smoke detector starts beeping. Remove the lid to make it stop since the test button is being held down by duct tape on the lid. Replace the yarn and the lid after each activation to reset the alarm.
