Firefighters were left surprised when a call to a smoke alarm at a house turned out to have been triggered by burning sage during an exorcism.
Fire crews were called to the house on Kirkstone Court, Long Eaton, Derbyshire at about 12:00 BST on Monday.
They said when they arrived, they saw a man dressed in a religious outfit who said an exorcism had been carried out to get rid of "an unwanted presence".
Crews carried out a routine search but confirmed it was a false alarm.
Watch manager Pete Hopkins, from Nottinghamshire Fire and Rescue Service, who attended the call, said: "We didn't find any fire or ghosts, which was a relief."
The burning of sage is an ancient ritual, which some people believe can cleanse spaces.