Seven sons of Sceva, a Jewish chief priest, were doing this.
The preachers of the gospel were sent forth to carry on a war against Satan, and therein Christ went forth conquering and to conquer. The casting of evil spirits out of those that were possessed was one instance of Christ's victory over Satan; but, to show in how many ways Christ triumphed over that great enemy, we have here in these verses two remarkable instances...
Commenting on Acts 19:13-20
And the man in whom the evil spirit was,.... Being agitated by him: leapt upon them; with great agility and force, and laid hold on them, and struggled with them, and beat and wounded them, and stripped them naked: and overcame them, and prevailed against them; the Alexandrian copy, Beza's most ancient one, and some others, and the Vulgate Latin version read, "and overcame both"...
Verse 14. One Sceva. Sceva is a Greek name, but nothing more is known of him. Chief of the priests. αρχιερεως. This cannot mean that he was high priest among the Jews, as it is wholly improbable that his sons would be wandering exorcists. But it denotes that he was of the sacerdotal order.