Major exorcisms are a whole different ball game. Unlike minor exorcisms, major exorcisms are used exclusively to expel demons from the bodies of possessed persons. (They are NOT used to expel human ghosts from houses.) However, when the Catholic Church becomes involved in a case, the same ritual used for major exorcism may be employed to clear a property of demonic presences. The intensity of the minor exorcism in such cases may equal that of a major exorcism.
The influence of a human discarnate (as opposed to a demonic entity) on a living subject is considered by the church to be a psychiatric problem associated with behaviors, addictions and activities on the part of the patient (host). This is the reason that the church always carries out a detailed investigation prior to assigning an exorcist.
Major exorcisms are always carried out by specialized religious clergy who are especially pious, because any past sins will be used as leverage by the demon against the priest or shaman. No human being can face down a demonic angel, so major exorcisms are always done in the name of the deity, God, the Great Spirit, Jesus, Mohammed or other holy avatars, and never in the name of the exorcist him/herself. Exorcism is an exceedingly dangerous business for the exorcist, and more than a few have have been possessed or seriously injured themselves during an exorcism. Very few escape without some form of lasting injury, either to their bodies or to their minds.
The demonic does not possess property or objects, although demonic entities may infest a dwelling if a current or previous occupant has invited it in. Demons possess people! Demons want only to possess human bodies that contain souls, and a house has no soul. In the words of Rev. Christopher Neil-smith in his book The Exorcist and the Possessed:
“[Major] Exorcism is not intended essentially to deal with ghosts or even houses, but with states of soul of living people molested by evil spirits. . . . Evil comes through people and [exorcism] only has a secondary or residual effect on places or houses. Places are affected because the people who lived there enacted evil deeds.”
According to demonologist Ed Warren, about half of the cases he investigated involved “inhuman” spirits (devils and demons). On the other hand, the Wicklands, during their 40 years of dealing with obsessed psychiatric cases, never ran into a single demon. I suspect that the differences in what they saw are what one might call sampling errors. A demonologist is called in by church authorities on cases that are violent and in which a demon is suspected of causing the problem. The Wicklands treated the hallucinations of ordinary people afflicted with mental illnesses. They may have been crazy, and they may have been obsessed or even possessed by ignorant spirits, but none of them showed signs of demonic possession.
Dr. Richard Gallagher, a psychiatrist who has treated a score of demonically possessed patients said in his book, Demonic Foes:
“Many believers are surprised when I state that of the 25,000 or so formal patients I have assessed in depth over the course of my career during my normal professional workday, none were possessed. The cases I’ve concluded were possessed were always either sent to me by clergy or found me only after hearing of my expertise first and seeking me out on their own.“
Demonic Foes; my 25 years as a psychiatrist investigating possessions, diabolic attacks and the paranormal: Gallagher, Richard; October 6, 2020; HarperCollins publisher