"My grandmother lived the latter years of her life in the horrible suspicion that electricity was dripping invisibly all over the house. It leaked, she contended, out of empty sockets if the wall switch had been left on. She would go around screwing in bulbs, and if they lighted up, she would fearfully turn off the wall switch and go back to her Pearson's or Everybody's, happy in the satisfaction that she had stopped not only a costly but dangerous leakage. nothing could ever clear this up for her."

Source: James Thurber (1996). “James Thurber: Writings & Drawings (including The Secret Life of Walter Mitty)”, p.587, Library of America