Kevin Morris received hidden Binary transmissions from the family television set, which he promptly transcribed. Although the sections of the code had random effects, when the sheets of paper he wrote on were laid out, they created the image of his abductee Sister, Ruby Morris. (TXF:"Conduit").
While incacerated after his apprehension by Mulder and Scully, Darren Peter Oswald was able to change television channels using his power over lightning and electricity. (TXF:"D.P.O.")
During a series of murders in New Hampshire caused by astral phenomena, many television sets in proximity played the same old time movie on different channels (TXF:"Syzygy")
The water supply of a town was poisioned with a chemical which left the users susceptible to subliminal images via modified cable signals. Once seen, these images triggered murderous paranoia (TXF:"Wetwired")