Power conditioner needed????

Here's the deal. The picture on my 56" Samsung DLP has a green tribal graphics pattern that comes and goes. It is there with satellite or DVD source. I turned appliances on and off. I have flipped breakers on and off. At one point, the only breaker that was still on was the one for the TV. Finally with just the one breaker on, the distortion went away. I slowly turned breakers back on one at a time and there was no sign of the problem returning................until 30 minutes later. I went through the whole ritual again to no avail. Finally around 2AM the problem went away only to return the next day. I have concluded the problem must be with some electrical thing a neighbor is using. That is my best guess at this point, but I don't know squat. What I know for sure is I cannot track the problem down to anything in my house and it goes away late at night. The house is in a semi rual community with underground utilities.
I took the TV to another house and left it on for 3 days. No issue at all.
So, here is the question................do you think a power conditioner will help? If so, which one?