Why does there seem to be 120V current going through my cable TV connector?

A bright blue spark would not indicate 120v. If that where the case you would fry the PC and yourself. The problem more then likely is in the grounding of the house electrical service itself. Many houses built in that era, are only wired with a hot and a neutral. To find out. Just go to your service panel and check the wires going into the panel and the breakers/fuses. Id the wires going in, are in a black cloth, posiibly just a two wire system. You should know what a ground wire looks like, it void of insulation. (bare copper). Another possible explanation could be static electricty. If your home has forced air heating. You should at least install a surge protector on your PC.

First, whatever it is, you should regard it as dangerous.

It could be a problem with either the AC outlet or the cable ground. And the problem could be that the ground is floating, or somehow connected to AC power (the HOT wire). Get an electrician friend to put a voltmeter on it, or buy 1) a voltmeter ($10 to $20 at Sears, Radio Shack, hardware store), 2) a 3-prong outlet tester and 3) a little AC test light.

Your outlets are probably two-prong, without ground. Or if they were retro-fitted to 3-prong. The retrofit could have been done wrong. Try the 3-prong outlet tester on the outlet and see what it indicates. Then try the voltmeter and/or the ac test light from the cable ground (shield) and the chassis case (ground). BE CAREFUL! If the meter indicates 120V (or the ac test light turns on), you have a big problem and need to get someone who knows this stuff to help.

Ya, trace that line throughout the house. Sometimes you get a slight zap but a 120V, that's not good. It could be a splitter that's not grounded right, or worse yet they had a signal amplifier to boost the signal. I worked cable for 5yrs, and my suggestion is to rewire the cable to where it goes. Conversely if its a straight line to the cable link, tacked on the outside, then you could have a problem with the digital box on the outside where your cable come in. Hope that helps.

Sneak into his abode and thieve all his remotes. probability is, he's not previous sufficient to keep in thoughts even as human beings easily had to upward thrust up off the settee, and walk to the television to regulate the channel. And if he does keep in thoughts, he's in all likelihood too previous and lazy to easily do it.