8 volts where there should be 0 volts. other appliances were ruled out by flipping each breaker systematically in the house, until all breakers were flipped, and none of them affected the voltage.
Still not specific enough.
8 Volts were measured from where to where?
Ground prong of receptacle to shield of cable?
Neutral of equipment to case of equipment?
Ground of receptacle to neutral of receptacle?
Case of equipment to kitchen sink?
We are not there. The only thing we can do is play 20 questions.
Did the 8V ever disappear?
Right now I would lean toward there being an issue with the neutral and ground in your neighbor's house. For example, if they lost their neutral connection to the utility, they have a faulty cable box and the cable company ground is poor, it is possible that current, from the neighbor is flowing 'out of their house' on the cable and coming 'into your house' before going back to the utility via your neutral-ground connection.