Exorcism
In Catholic Christianity, exorcisms are performed in the name of Jesus Christ. A distinction is made between a formal exorcism, which can only be conducted by a priest during a baptism or with the permission of a bishop, and "prayers of deliverance" which can be said by anyone.
The Catholic rite for a formal exorcism, called a "Major Exorcism", is given in Section 11 of the Rituale Romanum. The Ritual lists guidelines for conducting an exorcism, and for determining when a formal exorcism is required. Priests are instructed to carefully determine that the nature of the affliction is not actually a psychological or physical illness before proceeding.
Vince Lampert
As a noted expert on exorcism, who is willing to be published in the media about his work, Father Lampert was questioned about the difference between exorcisms that are authorized by the local bishop, compared to fee based "private exorcists" that work independent of the church. Lampert has met with other exorcists in Rome during meetings with the International Association of Exorcists. When he was appointed as an exorcist in 2005, there were perhaps only 12 exorcists in the US. Today, there are more than 50 that he knows personally in the USA. As one of the noted authorities on exorcism, he was interviewed in documentary movie "The Rite of Exorcism: Myth, Mystery & Hope" along with other noted exorcists like Fr. Gabriele Amorth and Fr. José Antonio Fortea. His first exorcism case as documented in an episode during the 2013 season of the cable television network Syfy series "Paranormal Witness." When the Fox TV Show "The Exorcist" was released a Fox TV News crew did a two minute interview with the exorcist that is sought out for interviews from around the world for his commentary on the series. Father Lambert was quoted in an article by "The Atlantic" that as of October 2018 he had received 1,700 phone or email requests for exorcisms, the most he had ever in a year.