The incident took place around 11 am, a fire department official said.
Two fire tenders of the Ludhiana Municipal Corporation were used to douse the fire.
By the time the flames could be controlled, one Air Conditioner, a computer and furniture lying in the office were gutted, the official said.
A caretaker present at the office had informed the fire department about the incident.
Electric short circuit is believed to be the cause behind the fire, Fire Officer J S Singh said.