I have seen two instances of demonization ("Demon possession" is an unfortunate KJV mistranslation).

One was a mid teens gal who's total personality, and appearence suddenly changed and she became wild and uncontrollable after a meeting until Samuel Thomas (who was the speaker that evening in the Sidney, Ohio FGBMFI meeting) came out in the Holiday inn parking lot and ministered deliverance to her. SInce my AoG youth group was there at the meeting they all watched it too, and afterwards we went to her house and called the blood of Jesus through it since we had the sense of the presence of the demonic there also. I lost my position as Youth leader because of that one - the AOG in '74 chose NOT to believe that there was demonic activity in rural Ohio. One of the gals in the youth group discovered that she could "feel" demonic presence in her hands (they became ice cold and sweaty).

The other one was the sister of one of the folks in the Celina AoG church, about 1976, who was being driven to suicide by a totally dominating spirit of fear. As a last resort, the pastor and the member got her over and ministered deliverance. The church member prayed exclusively in tongues and decribed the "pushing" sensation against the demonic entity, and a great "holy anger" focused on it - AND the lifting of the burden when the thing left. The sister was immediately "O.K." but had a week of so of shadows with nothing to cast 'em, things moving in her house, and her piano playing by itself, which she opposed in Jesus' name - and now as of 3 years ago (2003) she was still "delivered" and without oppression.