A switch plate was hot to the touch when I turned the lights off last night. This switch plate controls 6 can lights and a sliding dimmer. The wiring was completed by a professional electrician, as part of an addition to our home 6 months ago. This concerns me because I have never felt a hot swith plate in the 20 years we have been in this house. My instinct tells me to call the builder and request a service call from an electrician.

I would have it checked out by a pro. The dimmers can cause heat to be generated but so can loose wiring.

Have you ever used a slide dimmer before? They all generate some heat but like HVAC says, an electrician should come out from your contractor to check it out.

Definitely have it checked out

With only 6 lights, I wouldn't think you could have put big enough bulbs in to over load the switch. If you did recently put in larger bulbs, you may want to change back before calling the builder. Most fixtures have a limit on how large of bulbs you should use.

Labman makes agood point since we have no idea how many watts you are pulling. Are these 6 lights anything like 150 watt spots?

Does anyone know... do they still make the 'rheostat' style dimmers, or can you only buy the newer solid state voltage varying gizmo's? The older resistor style ones got quite warm - and were hottest when the lights were dimmed.

Rheostat dimmers are still available. I use one to control the ceiling fans in the garage during the summer. I also installed four of them last year in my other home in Indiana. I prefer the turn type to the slide type but the best is the push on and off turn rehostat type since you do not have to change the settings to turn it off or on.

I trust your instinct, shut the switch off, and leave it off until it can be checked out.

You should learn that the dimmer is intended to get hot while operating normally, but since we don't know how hot it is, best to have it checked.

Dimmers do get hot, one thing you can do is install it in a metal outlet box instead of plastic, that will absorb a lot of the heat.

Although your wiring should be good for at least 1440 watts, the dimmer may not be.

Many common dimmers are 300 or 600 Watts. 6 52watt bulbs=312 watts.
with power removed, remove dimmer, if 300, get a 600?