Luke wrote:

Our TV reception, from a roof antenna, was intermittently flaky.
Trying to find the problem, I got a shock when I touched both the TV
F-connector and coax cable antenna lead. So I put a tester on and to
my surprise got a 75 volt reading.

It's also 75 volts between the TV F-connector and the outlet ground
plug hole or outlet screw. And, there's 75 volts between any connector
on the TV and any of these grounds. I'm also getting ~40 volts off the
VCR F-connector, and ~50 volts off the DVD player *housing*.

Best I can determine this is the case with all house circuits. I
plugged the TV into several, using extension cords, and carried the
DVD player around to plug it into all circuits. I also get ~30 volts
off the housing of an old stand mixer in the kitchen.

This isn't normal, is it?

I checked as many outlets as I could get to with a GB plug-in circuit
tester, and all test correct. All outlets are at 125 volts. I opened
the main panel and the one subpanel to see what I could see, and all
looked right, though I really don't know what I'm looking for here.

What would cause "hot" appliances, and how do I track this down?

Thanks!

Aside from all the other suggestions, don't forget that the cable system
gets its power from the cable itself. That's on the order of 75 volts
send down the large center conductor of the cable. You might need a
visit from the Cable Guy to check it out.