Just to follow-up since the replies here are great. Thank you.
I had an electrician check out the box in question. He said that all connections at the switch and a wire nut connection in the box were tight. He said there was no signs of overheating. He said he could not detect an odor, however, I still do when I get my nose right up to the switch after toggling. So I suppose this is a normal thing as you guys describe. I think he may have thought I was a bit looney that I was sniffing light switches this closely.
He said an electrical odor is something one would have no question that something is dead wrong. He relayed a story about a customer and a lingering electrical odor caused by overheated outlet used for hair dryers and curlers etc. The odor remained even after the circuit in question was powered off for a few days.
