Firefighters were called to a suspected house fire in Godmanchester on Saturday (July 5) which turned out to be a flea smoke bomb.
Neighbours above the ground floor flat on Stokes Drive spotted smoke which had activated the fire alarm.
Firefighters arrived at 3.40pm and forced their way in through a back door to investigate and found the cause was a device that killed fleas.
Watch commander Dan Martin said: “We would urge residents to ensure they follow the instructions when using devices like these and a good idea would be to inform their neighbours so they are aware in case they see smoke.”
The householder, who had left the property, had failed to identify instructions to turn off smoke alarms when using the device.