The fish tank thread got me thinking about this. I'm sure I have them, every home does, I've heard them and tried to control them, but what could I be missing? I don't necessarily mean the odd bits, but what are some ordinary things that would be in practically every household that I may be overlooking? I don't have a huge problem, but I do hear things I'm thinking I may be able to control if I knew what they were or what they could be. I'm aware of: Fish Tanks (don't have any) Plasma TVs Electric motors (blenders etc) Fluorescent lighting Microwave ovens Neon lights Laptop chargers Dimmer switches?