Parapsychologist Loyd Auerbach discussed his field work into various types of ghostly phenomena. While cases he's investigated frequently prove to have prosaic explanations for some or all of the reported phenomena, there is also evidence for the paranormal which falls into different categories which include: conscious entities, imprints and poltergeists, he explained.

At the Moss Beach Distillery in Northern California, known for its hauntings by the "Blue Lady," Auerbach said he actually felt a female ghost "walk through him" several times while she giggled and seemed to be deliberately interacting with him. Psychics who accompanied Auerbach confirmed what he was experiencing, he said. Poltergeist activity such as objects flying off shelves has been traced to living humans who release stress or anger in a kind of "subconscious temper tantrum," Auerbach reported. Along those lines he believes that "entities" that arise from Ouija boards and the like, are also subconscious psychological manifestations of the participants.

Imprint hauntings are often related to tragic episodes, in which a very emotional event can leave a kind of tape loop in a specific location, he said, adding that individuals will vary in their ability to sense such traces.