Sounds like you house might have a shotty wiring system to it. I would check the plugs to make sure they are grounded well...if not, you will probably want to call an electrician in and have the whole house re-wired.
I was working on my friend's house (older 60-70s house) and we found that they guy had wired the bedroom ceiling fan (from the light switch) with 18guage speaker wire (not even rated for in wall)...needless to say we tore that all out and rewired it correctly. Luckily the rest of the house looked pretty good (albeit old).