As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) SMOKE IN THE CABIN WAS DETERMINED TO BE FROM THE LANDING LIGHT SWITCH. SWITCH WAS SHUT-OFF BUT CONTINUED TO SMOKE. ONLY WAY TO STOP SMOKING WAS TO TURN OFF THE BATTERY MASTER AS THE CIRCUIT BREAKER IS OF A TYPE THAT CANNOT BE MANUALLY PULLED. NEW SWITCH AND CIRCUIT BREAKER WAS INSTALLED AFTER AIRCRAFT WIRING AND LANDING LIGHT CHECKED SERVICABLE.