This is a sensitive subject.
Casting out of demons was the healing and cure of persons of psychiatric diseases or psychological disturbances two thousand years ago. It requires a certain gift of the Holy Spirit, called discernment of spirits, a gift which is, according to Church teachings, not given to all.
Once upon a time, there were seven holy orders in the Church; now there are only two, deacon and priest. The order of Exorcist has fallen into disuse, and thus, casting out of demons is no longer practised in any of the Post-reformation churches.