One thing--check the cable TV ground. The cable company is supposed to ground the cable at the house (usually) but the installers will sometimes just make a connection and not check to make sure it is a good ground connection. I've seen many examples of ground connections made to disconnected ground wires or other poor grounds. One was even a simple strap wrapped around a conduit--that was plastic!
Plastic conduct connection!! LOL Now that's funny right there!!!