Then here's your answer:

http://ths.gardenweb.com/forums/load...092410993.html

I've had this problem off and on where my dining room area would randomly smell like fish, and I couldn't figure out where the smell was coming from. I keep the place really clean, and couldn't figure out what habit was causing it to happen every few weeks. Then I read this.

Starting smelling plugs and lights, and lo and behold, it's my dining room light fixture that I don't turn on all the time. I think whenever I leave it off for a long time and then turn it on, it does this fishy thing. Very odd. Nice to know what it is though. Guess what's getting replaced soon? Ha.

Just thought I'd share