A team of ghost hunters caused concern at a museum in King's Lynn after leaving an electronic device in the premises overnight.
Staff at True's Yard Museum found the object in one of its fisherfolk cottages in North Street, on Sunday, September 12, during a Heritage Open Day.
The box containing the device, which played music, was collected on Wednesday afternoon by the ghost hunting team.
A Twitter message from the museum said: "So we found this box in our fisherfolk cottages on Heritage Open Day.
"Leaving untested electronics in a Grade 2 Listed building is irresponsible.
"It could have caused a fire."
The museum added: "It might seem pretty harmless but it meant our poor staff had to search the rest of the premises and make the decision (at the end of the busiest day of the year) whether to call the police because it could have been an explosive device."
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