Nicene and Post-Nicene Fathers, Ser. II, Vol. XIV:
The Canons of the Councils of Ancyra, Gangra, Neocæsarea, Antioch and Laodicea, which Canons were Accepted and Received by the Ecumenical Synods.: Canon XXVI

Canon XXVI.

They who have not been promoted [to that office] by the bishop, ought not to adjure, either in churches or in private houses.

Notes.

Ancient Epitome of Canon XXVI.

No one shall adjure without the bishop’s promotion to that office.

Balsamon.

Some were in the habit of “adjuring,” that is catechising the unbelievers, who had never received the imposition of the bishop’s hands for that purpose; and when they were accused of doing so, contended that as they did not do it in church but only at home, they could not be considered as deserving of any punishment.  For this reason the Fathers rule that even to “adjure” (ἐφορκίζειν) is an ecclesiastical ministry, and must not be executed by anyone who shall not have been promoted thereto by a bishop.  But the “Exorcist” must be excepted who has been promoted by a Chorepiscopus, for he can indeed properly catechize although not promoted by a bishop; for from Canon X. of Antioch we learn that even a Chorepiscopus can make an Exorcist.

Zonaras notes that from this canon it appears that “Chorepiscopi are considered to be in the number of bishops.”

Van Espen.

“Promoted” (προαχθέντας ) by the bishops, by which is signified a mere designation or appointment, in conformity with the Greek discipline which never counted exorcism among the orders, but among the simple ministries which were committed to certain persons by the bishops, as Morinus proves at length in his work on Orders (De Ordinationibus, Pars III., Ex. XIV., cap. ij.).

Double is the power of devils over men, the one part internal the other external.  The former is when they hold the soul captive by vice and sin.  The latter when they disturb the exterior and interior senses and lead anyone on to fury.  Those who are subject to the interior evils are the Catechumens and Penitents, and those who are subject to the exterior are the Energumens.  Whoever are p. 148 occupied with the freeing from the power of the devil of either of these kinds, by prayers, exhortations, and exorcisms, are said “to exorcize” them; which seems to be what Balsamon means when he says—“‘exorcize’ that is ‘to catechize the unbelievers.’”  Vide this matter more at length in Ducange’s Glossary (Gloss., s.v. Exorcizare).

This canon is found in the Corpus Juris Canonici, Gratian’s Decretum, Pars I., Dist. LXIX. c. ij., Isidore’s version.