Christopher Galt, 25, admitted voyeurism after footage taken from the device showed him installing and checking on the equipment on several occasions.
Householders became aware of the camera when they spotted a green flashing light coming from the extractor vent above the bath.
Initially they thought it was some kind of alarm but on closer inspection they discovered it was a USB camera. DC Steve Jenkinson, of Lancashire Constabulary’s public protection unit, said: “The people who discovered it checked to see what was on the camera.
“When they saw that it was themselves they were shocked and immediately reported it to the police.”
A peeping Tom installed a hidden camera in a bathroom to spy on people using the facilities.
However he later pleaded guilty to voyeurism at Preston Crown Court.
The householders, who lived in a rented property, left the house that day and have since found other accommodation.
DC Jenkinson said it was not possible to say exactly how long the camera had been hidden in the bathroom but it could have been there for a number of months.
Galt was handed a community order and ordered to undergo two years supervision with the probation service.