Little white Sears 9" SS color set

[zenithfan1]

They protect sensitive electronics from voltage surges, supposedly. I think the one in your set is bad, hence the spark jumping to other things. There may be a bad cap or something causing fluctuations in voltage, I've never seen one spark in a tv set. check for any breakdown of insulation for the HV section, once you have an arc, usually a carbon track will form making a conductive path to whatever is being arced to, like a nearby ground. In your case something on the neck board. After re-reading your post, you may be right about the CRT grounding. It looks like a charge is building up and going to whatever ground is closest.