Burmese folk religion
These exorcists, or "ahletan hsaya", are said to possess powers that can fend away or challenge these evil demons. These exorcists were often seen as very holy, because they had to be to combat troublesome spirits. They attempt exorcisms by giving the nat offerings. As an interesting overlap with Buddhism, exorcisms can be performed by holding the Buddha up to the possessed person, in an effort to have the Nat flee. If the exorcist cannot banish this spirit alone, they often ask for the assistance of the nat-kadaw. Sorcerers, or "weikzas" also harnessed the power of these nats through many complex rituals, to gain their own supernatural powers.
International Association of Exorcists
Although the membership is restricted and exclusive, by 2000 there were over two hundred members, who meet bi-annually in Rome. The association sends out a quarterly newsletter where members can tell of particularly interesting or difficult cases. An exorcist priest must have the permission of his bishop to join. 
Within the Roman Catholic Church a priest may only do an exorcism with the express consent of his bishop or local ordinary, and only, to the extent necessary, after an examination of the patient by doctors and psychiatrists in order to determine that the affliction has no natural origin. A priest is required by canon law to be devout, knowledgeable, prudent, and possess integrity of life.