As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LANDING LIGHT SWITCH STUCK IN ON POSITION. SUSPECT INTERNAL ARCING & WELDING OF CONTACTS. THE OVERHEATING CAUSED BY THE ARCING CAN CAUSE THE SWITCH BODY TO MELT, BUT DID NOT IN THIS CASE. NO SIGNS OF HEAT DAMAGE OF EXTERNAL SWITCH SURFACE WERE FOUND.