Church leaders have also doubled the number of exorcists available in the city, which is the largest diocese in Italy, Sky News reports.
Chief exorcist Mons Angelo Mascheroni said: "We receive a lot of requests for names, addresses and phone numbers. That's why we have set up a switchboard in our [offices]."
The line is manned Monday to Friday afternoons and refers callers to priests and exorcists who can help.
Mons Mascheroni said one priest had been inundated, seeing as many as 120 people a day. The church has increased the number of exorcists in the region from six to 12 as a result.
However, he added: "Genuinely diabolical cases [of possession] are, in my experience, very rare."
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