Demonologists have nothing to do with the paranormal; according to Bishop James Long, the devils belong to theology.
We learn from Paralearning in Modern Demonology for Paranormal Investigators that the investigation process and communication with ghosts and devils are similar, like
- How to conduct a séance
- How to call out to spirits
- Knock once for no, twice for yes
- etc.
The devil and the ghost are both spirit entities.
The difference lies in the surrounding elements; devils are uncomfortable with crucifixes unless they reveal their identity, at which point you’ll notice the difference.
And, of course, the devil lies, so hard to set them apart unless you know how to deal with the devil.
Michel de Notre-Dame