Ghosts or personates family members. (1) Thought to impersonate deceased or ghosts that trouble houses or solitary places(hauntings). Familiar spirits. cursed objects or poltergeist activity. It is my belief, many of these are seen on the ghost chaser shows on TV. These could also be those assisting the mediums during family seances, where they have insight on family history and knowledge.
Umbrae Mortuorum (Dead Shadow or Shadow People):
Shades of the dead. One of the earliest encounters with the shadow people was reported by the editor of the Paranormal magazine, Richard Holland. (2) Normally there is a dark countenance and malevolent feelings that are often reported in association with these creatures. Per Jason Offutt, author of ‘The Darkness Walks’, the most common [type of] shadow person encounters: a blacker-than-night, human-shaped shadow that people see walking through their bedroom, hallway, living room, etc. (3)
Follow certain people to trouble them from outward during the day. (incubus/succubus). Also could be mental illness being oppressed by spirits. We see an example found in 2 Corinthians 12:7-8, where Paul has a ‘thorn in the flesh’.
7 And lest I should be exalted above measure through the abundance of the revelations, there was given to me a thorn in the flesh, the messenger of Satan to buffet me, lest I should be exalted above measure. 8 For this thing I besought the Lord thrice, that it might depart from me.
Obsession is an advanced form of oppression to the believer.
The spirit enters inwardly in the person to trouble them. Illusionary deception to make them believe they are travelling, via astral projection, prophesy, ECT. Spirits and entities do not walk to up to a person and ask them if they want to be possessed. Instead, they find a weakness or a door through traditional family behavior or reckless behavior of the individual. The person’s active free will must be breached. They usually seduce a person with something simple and almost innocent unless they have done something that they have tremendous shame or guilt over. (4)
(1). King James. King James Demonology: Modern Translation. Retrieved from https://books.google.com/books?id=_4PfDQAAQBAJ&pg=PT47&lpg=PT47&dq=king+james+identified+4+categories+of+spirits&source=bl&ots=6nvKmTyVuT&sig=FlF893jLF01BON76Jx-_sHgD2qg&hl=en&sa=X&ved=0ahUKEwjSgL2u1ObVAhUP92MKHQ_vCOEQ6AEINzAC#v=onepage&q=king%20james%20identified%204%20categories%20of%20spirits&f=false
(2). Leo Ruickbie. A Brief Guide to the Supernatural: Ghosts, Vampires and the Paranormal. Retrieved from https://books.google.com/books?id=G7_ABAAAQBAJ&pg=PT21&lpg=PT21&dq=Umbrae+Mortuorum++shadow+people&source=bl&ots=gJvvSJ9IHr&sig=0p5P1NnrTzQM09Zc4moHnSCIXnw&hl=en&sa=X&ved=0ahUKEwiXrMfD2ObVAhUOyWMKHYgbBqcQ6AEIPDAH#v=onepage&q=Umbrae%20Mortuorum%20%20shadow%20people&f=false
(3). Stephen Wagner. An interview with author Jason Offutt about these eerie entities. Retrieved from https://www.thoughtco.com/shadow-people-what-are-they-2594067
(4). Spirit Attachment and Possession Symptoms. Retrieved from http://www.texasghostandspirit.com/parasitic-entities/entity-and-spirit-attachment-and-possession-and-symptoms/