Unplug the HDMI cables (one end only) and then the power plug. Wait 10 or so minutes then apply power and see if it clears up. If not look in the manual for resets and try that. Next up is getting repair estimates.
Be sure that all sources do same so you are not calling for repair on the wrong part.
Having a problem with my LG TV. Picture is flicking and ghosting at the same time. Happened out of nowhere. Was watching a show, went to the next episode and bam, problem started.