The Charles Rennie Mackintosh Society (CRMS) is seeking volunteer ghost hunters willing to pay a donation to sleep in the Mackintosh Church at Glasgow's Queen's Cross as they seek to raise £10,000 to refurbish the building.
Since the church opened its doors to the public in 1899, several strange occurrences have been noted.
Most recently, the CRMS's director, Stuart Robertson, captured an image in a photograph which appears to resemble the spectre of the renowned architect himself.
The challenge is part of a fundraising campaign by the society to raise £10,000 to develop a new performance space within the church.
The CRMS hopes to transform the building into a new arts centre in an area of Glasgow currently undergoing a period of renewal and regeneration.
The church was built in 1896 for the Free Church, and it bears many of the hallmarks of Mackintosh's work,with dark wooden benches and distinctive floral motifs.
Those taking part will be the first people to have spent the night in the building, which is open to visitors during the day.
Mr Robertson said: "In the evening, when light spills through the church, it is quite amazing.
"Upon close inspection of a photograph I took of this, an image that has an uncanny resemblance to Charles Rennie Mackintosh, even his distinctive moustache, is clearly visible.
"On the right there is also the clear outline of what looks like a fairy.
"This left me very uneasy; I can testify that there has been no manipulation of the photograph."
The campaign to refurbish the church has so far raised £2000, and all of the work planned within the building is in consultation with Historic Scotland and conservation specialists.
Those wishing to get involved, or those who want to explore the other gift options available as part of the campaign, are urged to visit www.igg.me/at/crmsociety or call the society on 0141 946 6600.