The Third Doctor was attacked by a plastic phone cable animated by the Master using Nestene technology. He was saved when the Brigadier disconnected the phone. (TV: Terror of the Autons)
There were cables in LINDA's base, which Colin Skinner advised his fellow members to mind when the lights went out. (TV: Love & Monsters)
During the Great War, the Dalek invading Mars were defeated by a virus, possibly derived from the Movellan virus, that attacked the insulation of the cables in their electrical systems. Although the Daleks eventually discovered an antidote, they retreated from Mars. Combined with their expulsion from Venus, the Daleks were driven back from the solar system, but the war continued elsewhere in the galaxy. (PROSE: The Whoniverse)