Firefighter Scott Johnson, 43, fought the DUI charge but jurors only needed 45 minutes of deliberating to find him guilty.
Johnson was working as a bouncer at a bar and several witnesses testified at the trial that he had been drinking. After the bar closed, he was called to a fire at approximately 2:30 a.m., but the call turned out to be a false alarm.
A police officer -- who saw him at the bar earlier in the night -- saw him driving the fire truck back to the station and confronted him as he parked the truck in the garage.
Johnson took a blood test which showed he had a blood alcohol level of 0.098, just over the legal limit, according to the report.
He has been suspended from the fire department since his arrest, but Fire Chief Jerry Johnson told the news station that he wants Johnson to be a volunteer firefighter in Madison again.
Johnson is scheduled to be sentenced on Jan. 3 and faces up to one year in jail or a $2,000 fine.