The front passenger seat heating system experienced a catastrophic electrical malfunction. While the vehicle was started and parked in our driveway, the front passenger seat suddenly developed an extreme hot spot and became engulfed in flames even though the heated seat switch was in the OFF position and had not been activated. The failed heated seat component has been retained and is available for inspection. The vehicle has not been inspected by a dealer or service center because the incident occurred at our residence and the vehicle is currently undriveable due to burned electrical wiring. Attempting to start or operate the vehicle could result in an electrical short because of the exposed and damaged wiring caused by the fire. Both the local police department and fire department responded to the scene and inspected the vehicle. There were no warning lights, warning messages, unusual odors, or prior symptoms indicating a problem before the fire occurred. This incident represents a significant fire hazard because the heated seat ignited without being turned on. Had this occurred while the vehicle was being driven or while occupants were seated in the vehicle, it could have resulted in serious injury or death due to burns, smoke inhalation, or loss of vehicle control. Likewise, had the vehicle been parked inside an attached garage, the fire could have spread to the residence and placed lives at risk.