# Are these three-way switches?

I have 2 bedrooms and I want to replace the light switch for a dimmer. I though it would an easy job for a beginner like me but after I opened the first switch, I realized there was a 3 wires (I was expecting 2 + the ground wire).

After reading on the switch, I determined the red wire is a common wire (on the old switch, it was plugged in a "quick connect" hole with the letter "C"). The second room also have the same setup.

I'm a bit confuse. I though the common wire was for a three-way switch only. Considering that each bedrooms switch are independent and that there's only one switch in each room, can someone help me understand if I have a three-way switch or not.

* EDIT * Please note that their was no Common wire in any of my switches. See accepted answer for details.

For the record, here's a schema of my final circuit (I have a ceiling light but the schema is still valid)

• The switches are "interdependent"? Do you mean that if you toggle one switch, the lights in both rooms change state? Aug 20, 2014 at 12:35
• A photo or diagram might be helpful. Aug 20, 2014 at 12:35
• @Tester101, no... I meant to say "dependent" (i.e. the switch has no effect on the light in the neighbor room). After TDHofstetter anwser, I realized the guy placed 2 wires under the same screw because he didn't want to do a splice. Aug 20, 2014 at 18:53
• Note that a three-way switch is just a two-way switch with one extra terminal. If you ignore the '2' terminal, the '1' and 'C' act as a normal switch. Mar 29, 2016 at 22:21