A real exorcism? Really? When police in Fremont County, Wyoming got a call from someone saying that a woman possessed by a poltergeist had stopped breathing after being sprayed with holy water, they rushed to the scene — likely out of curiosity.

The woman, who has not been publicly identified, is believed to have gone into cardiac arrest during an attempted exorcism at a home in central Wyoming. The people who were in the home upon the sheriff's arrival said that a demon bit people and broke things around the house. Responding officers were unable to find evidence of the broken items, nor did they see evidence of people being bitten.

The woman is reported to be in stable condition.

Exorcism is the process of removing demons or evil spirits from a person or area. In 2001, ABC News reported that exorcism was "thriving" in the United States. "By conservative estimates, there are at least five or six hundred evangelical exorcism ministries in operation today, and quite possibly two or three times this many," wrote Michael W. Cuneo, Fordham University sociologist, in his book entitled American Exorcism.

But not all of the exorcisms that take place today are like the ones that you saw in the famous 1973 film. The ritual doesn't necessarily involve tying someone down, loudly reading from the Bible, and tossing holy water at the subject, though some do. And, conversely, not everyone who receives an exorcism is possessed.

Mother Teresa, for example, was believed to be in need of an exorcism shortly before she died. The Archbishop of Calcutta, Henry Sebastion D'Souza, ordered an exorcism be performed on the Nobel Peace Prize winner in 1997. But in 2001, Roman Catholic priest Joseph Scerbo said that Mother Teresa's exorcism was likely because of the less serious problem of demonic affliction, not full-fledged demonic possession.

Many are skeptical about the concept of possession and whether some mental illnesses can be mistaken for demonic possession, but devout Christians say that the Holy Spirit guides them and makes them sure. "Through the Holy Spirit, you can tell it's more," Rev. J.R. Hall told ABC News.

Anglican priest Eddie Gibbs said he see tries to err on the side of caution, "If it's real to the person, you have to take it seriously. I do believe that there is an intelligence behind evil. We mustn't be gullible."