The idea of artificial man made ghost is not new. C.W.Leadbeater an exponent as a clairvoyant and psychic wrote about artificial entities created by rituals from some suspicious esoterical societies, basically speaking 'witchery'.
Now, perhaps on the current case entities would be created for other different purposes. In witchery artificial demons would have been created to haunt places and people (if the story is true).
This corroborates which Monica Brannan posted.