As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CRUISE FLIGHT, THE AUTO-PILOT CONTROL PANEL STARTED SMOKING AT THE HEADING SELECT SWITCH AND AREA OF PANEL BECAME HOT TO THE TOUCH. PULLED AUTO-PILOT CIRCUIT BREAKERS AND SMOKE STOPPED. FLIGHT CONTINUED ON TO MSP AND LANDED WITHOUT INCIDENT. REPLACED AUTO-PILOT CONTROL PANEL AND PERFORMED SYSTEM CHECK, GROUND CHECK OK.