In 1975, I visited the Edison & Ford Winter Estates in Fort Myers FL. It was 20 acres of historical buildings, historic gardens and the Edison Ford Museum. That day the guide mentioned that Edison's was trying to invent a phone with which one could talk to the dead. He started the project in 1920.
Back then, Americans were still reeling from the horrific casualties of World War I. Meanwhile, spiritualism, Ouija boards, and the slew of new technological inventions from men like Thomas Edison were capturing the national zeitgeist. All these converged when Edison told American Magazine that he was working on a device known as a “spirit phone” — in other words, a phone that would let the living communicate with the dead.