Two Wire doorbell systems
If you have a (2) wire doorbell system and cannot locate your transformer,  kindly contact us to make sure the Tommyknocker can be connected.

 Lighted Doorbell  switches
The Tommyknocker is currently not designed to work with a lighted doorbell switch.  We are working on a Mod that fixes this problem. In the mean time the Tommyknocker must be connected to an un-lighted switch.