Really, I tried turning the power off to the lights, but after trying all 5 unlabeled breakers, I gave up. One of those was the power to my entertainment system--not shared with the dimmer.

Though I've heard that dimmer switches can put enough noise on the wire it can affect devices anywhere on the same electrical feed.

Pioneer PDP-5020FD, Marantz SR6011
Axiom M5HP, VP160HP, QS8
Sony PS4, surround backs
-Chris