I have intermitant static interferance, seven seconds on then seven seconds off and so on, on all my tvs and radios both plug in or battery operated. If I turn off one partiular circuit breaker in my electrcal service box the static stops. No other circuit breaker has any effect. There is nothing on that circuit that would be emitting an interferrance signal. This interferance lasts weeks or months at a time and then dissapears alltogether only to return weeks or months later.