Sons of Sceva
The Sons of Sceva were seven sons of a Jewish high priest who were living in Ephesus.
Seeing that Paul had been driving out demons, they were driving out demons in the name of "Jesus, who Paul preaches" not knowing what they were doing. One day a demon answered them "Jesus I know, and I know about Paul, but who are you?" and then proceeded to jump on them and overpower all of them thrashing them so soundly that they ran from the house naked and bleeding.
When the events that had happened reached the populace, there was a sense of fear and the name of Jesus was held in high regard and knowledge of Him continued to spread widely. (Acts: 19:11-20)