We had a number of three way switches in our house that didn't work when we moved in. In fact, not one worked right. Whomever wired the house back in 1986 either didn't care or didn't know how to hook them up correctly. If you're not an electrician, or are not familiar with their standardized technical terms, the troubleshooting guides available might be confusing or useless. The information that comes with the switches seems to be the same. After pondering this issue for a few minutes the answer presented itself. 1. The "common" wire is either the load (to the light) or the hot wire (from the breaker box). 2. A "traveler" wire is just a wire that only connects to the switch. It doesn't lead to the load or the breaker box. To identify the "common" wires, the simplest method is to disconnect the switches and use a voltage detector pen (such as a Fluke VoltAlert Non-Contact Voltage Tester ) to find the hot wire. Once the hot wire ...