On June 17, 1999, at 1215 central daylight time (cdt) a Cessna 172N, N9419E, operated by a private pilot experienced a cockpit fire during landing roll at the Cloquet Carlton County Airport, Cloquet, Minnesota. The pilot and passenger who exited the airplane prior to it being consumed by fire were not injured. The airplane was destroyed by the subsequent ground fire. The 14 CFR Part 91 personal flight was operating in visual meteorological conditions without a flight plan. The local flight originated from Cloquet, Minnesota, at 1100 cdt. The pilot reported the flight was normal. During the landing roll the passenger informed the pilot that there were flames near the pilot's head. The pilot stated, "I glanced to my left and noticed some small flames lapping out from the upholstery on the lower portion of the doorpost. I stopped the plane on the runway, did a shutdown, and got out." The pilot stated he directed the passenger to go for help while he attempted to "swat" out the flames to no avail. The pilot stated the airplane was consumed by flames when the fire department arrived approximately four minutes after the landing. The wreckage was inspected by an Investigator from the National Transportation Safety Board, North Central Regional Office, and an Inspector from the Federal Aviation Administration, Minneapolis Flight Standard District Office. The wreckage was burned to such an extent that the cause of the fire could not be determined. Airworthiness Directive 80-04-08, effective February 16, 1980, encompassed the accident airplane. The purpose of the AD was, "To preclude the possibility of a fuel leak or an in-flight fire due to contact between a map light switch and an adjacent fuel line... ." The AD was to be accomplished with 25 hours time-in- service after its issuance. Procedures outlined in the AD were: 1) Visually inspect the fuel line and map light switch located in the left hand forward doorpost for chafing or arcing and replace damaged parts as necessary. If not already existing, provide at least .50 inch clearance between the map light switch and the fuel line in accordance with procedures in FAA Advisory Circular 43.13-1A. and 2) Install a cover (insulator), Cessna Part Number 0511080-1, over the map light in accordance with Cessna Single Engine Service Information Letter SE80-3 and Supplement #1 thereto, or both dated January 21, 1980. According to the aircraft records, this AD was accomplished on April 10, 1980. On June 11, 1999, the airplane underwent a 100 hour inspection. The aircraft total time in service at the time of this inspection was 7,768 hours. The map light switch on the pilot's door post was replaced during this 100 hour inspection. The logbook entry for this work reads, "Replaced map light switch with new (PN 5151- 1)." The mechanic who replaced the switch stated that he reviewed the AD when he installed the switch. He stated he made sure there was .5 inch clearance between the switch and the fuel line. He stated the insulator that he removed with the old switch was in good condition so he reinstalled the same insulator. In addition, he stated that there was a shrink wrap type shielding over the wires at their connection with the switch.