How is the tv setup, cable or Sat.?
If cable do you have a cable box or not?
What type of cables are you using?
Does it happen on all inputs, like you get lines with Cable/Sat box, gaming system, & bluray/DVD player or just one of them?
Is the tv hooked up to a surge protector? (power strips do not count)
Is it happening all the time or on/off?
If on/off, is it happened when your running something that is a power hog, like A/C, heater, power tools, garbage disposal, frig, ect.?
I think it is just bad grounding or could be dirty power, but need more info to help.
How do I get rid of scrolling vertical lines going upward on Panasonic TC-P50G25.