I have heared of this happening so many times to people of different backgrounds.
Most of the times it is something that can be explained like dodgy wiring to the tv itself
But there is always the spirit in the house explanation that is always a possibility ,some people say this is the beginning of a spirit trying to make contact ,or just there to be a pain in the *** but whatever it is it might be an idea to look into the history of the place you live in or the area you are in ,have you recently aquired an object that does'nt quite feel right or look right something like that ,as things like this can bring in some unwanted energy
Just a thought ''''''