I'm a paranormal investigator in Illinois, and I'm in the process of writing a book on "Ghost HUnting", this is an excerpt from my book:

In the previous paged of the book it was stated that Thomas Edison had no interests in the paranormal. But my research seems to say differently. Thomas Edison was a believer. There can be no doubt.

     In his speeches, journals, and writing he referenced many times about a machine he was building to try and communicate with the spirit world. In a 1920 essay, Edison wrote: "Now what I propose to do is furnish psychic investigators with an apparatus which will give a scientific aspect to their work. This apparatus, let me explain, is in the nature of a valve, so to speak. That is to say, the slightest conceivable effort is made to exert many times its initial power for indicative purposes. It is similar to a modern power house, where man, with his relatively puny one-eighth horse-power, turns a valve which starts a 50,000-horse-power steam turbine. My apparatus is along those lines, in that the slightest effort which it intercepts will be magnified many times so as to give us whatever form of record we desire for the purpose of investigation. Beyond that I don’t care to say anything further regarding its nature. I have been working out the details for some time; indeed, a collaborator in this work died only the other day. In that he knew exactly what I am after in this work, I believe he ought to be the first to use it if he is able to do so."

     Many say Edison was swindled by Spiritualists in the latter part of his life. This does not appear to be the case. Edison was a true scientist and ruled out no possibilities as an inventor. On November 29, 1875, when Edison was 28 years old, he called a press conference because he thought he discovered a "new force," described as an "etheric force" based on a mysterious force theorized by German chemist Baron Karl von Reichenbach (1788 – 1869). Reichenbach’s claim was that he discovered a force that could explain supernatural phenomena. He referred to this force “od” or “Odic” after the Norse God “Odin.” as. Edison researched Reichenbach's work and was curious. He looked for it and even thought he discovered it in 1875, but realized what he witnessed in an experiment was a natural arc of electricity.     

An interesting quote from Edison:

 "If our personality survives, then it is strictly logical or scientific to assume it retains memory, intellect, other faculties and knowledge we acquire on Earth. Therefore...if we can evolve an instrument so delicate as to be affected by our personality as it survives in the next life, such an instrument, when made available, ought to record something."
~Thomas Alva Edison