The Hermethicans were a species native to the planet Hermethica. A group of criminals led by the Wire discovered how to convert themselves into pure energy. (PROSE: The Time Travellers' Almanac) The Wire was sentenced to death by her people and eventually executed. However, she became a being of pure energy, and escaped via a mobile communications device, and fled across the universe to Earth in 1953 where she became trapped in a television set. (TV: The Idiot's Lantern)
Behind the scenes[]
The true form of the Wire or her species, beyond the fact that they were not naturally formless, is unknown, since she was using the image of a BBC continuity announcer that was on the television when she possessed it.