Is the Poltergeist 'Syndrome' the only type of paranormal phenomena that can really be proven?

There are few factual books written about poltergeist phenomena, John's Fraser's Poltergeist! A New Investigation Into Destructive Haunting fills that void, advancing and updating Colin Wilson's work Poltergeist!, this study's namesake from over 38 years ago. Fraser takes readers on a journey from the Borley Rectory to the Isle of Man, and grounds his readers in an historical overview of 'Poltergeist phenomena'. He examines where such events overlap with other paranormal investigations of 'apparitional' ghosts. What do they have in common, what do they differ? To answer this, Fraser looks to new research on paranormal events, never before published in book form. Fraser contends, perhaps controversially, that ghost sightings are and always will be ambiguous and near-impossible to prove, that only Poltergeist phenomena can be empirically verified.