The alarm was raised after people smelled smoke, and then saw it coming out of upstairs windows of the building, on Damrong Rd, Phuket Town.
As staff rushed to shift furniture out of the building before it smelled irretrievably of smoke, firefighters were called.
The fire was tracked on a short-circuit in an air conditioner installed above the upstairs ceiling, with burning plastic cable sheathing producing dense choking smoke.
The firefighters were able to put the fire out in 10 minutes. No on was hurt.
Governor Maitri Inthusut was not there at the time.