Doorbells are relatively safe to install because they use low voltage power instead of the full 110 or 120 volts of most circuits. That means you have to hook it up a small transformer that brings the normal house circuit down to between 12 and 16 volts, which is plenty to make the bell ring. As with all wiring, it’s easiest to install before you finish the walls, but it’s possible to run the cable through an attic or crawl space as well.
Things You'll Need
18-gauge electric wire
Turn off the electricity to your home, as you’ll be working with live wires.
Find a junction box that holds one of your existing home circuits. You might find one in the attic, crawl space or behind a cover on one of your walls. You’ll need this junction later to connect the transformer.
The low voltage transformer that came with your doorbell system has black and white leads coming out of it. Twist the black wire onto the black wire from your circuit using a wire nut. Do the same with the white wire.
Run the 18-gauge wire through your attic or crawl space from the doorbell to the junction box.
The low-voltage transformer that came with your doorbell system has a hot screw and a neutral screw (labeled as such). From the 18-gauge cable you just ran, connect the black wire to the hot screw, and the white wire to the neutral screw.
Choose a spot for the bell portion of the system somewhere along the path of the the wire you ran. It doesn’t matter where, just make sure you can hear the noise of the bell from wherever it is.
Cut the 18-gauge wire at the spot you chose for the bell.
Reconnect the black wire using another wire nut.
Connect the two remaining loose ends of the neutral white wire to the two terminal screws on the bell apparatus.
Fasten the door bell button in place using the screws that came with it.
Turn your power back on to begin enjoying your new door bell.
Some transformers will have a plug that can be plugged straight into the wall. In that case, just plug it into a socket instead of splicing it together at a junction box.