As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS ON A REPOSITIONING FLIGHT. PILOT NOTICED SMOKE COMING FROM OVERHEAD PANEL. AT ABOUT 9:45PM HE DECLARED AN EMERGENCY AND DIVERTED. LANDING SAFELY. THE ACFT HAS BEEN RETURNED TO SERVICE. INSPECTED OVERHEAD ELECTRICAL PANEL AND FOUND CAUSE OF SMOKE TO BE 2 EA LIGHT BULBS ARCING OUT ON RIVET IN UPPER LT CORNER. FURTHER INSPECTION OF REMOVED PANEL SHOWED CAUSE TO BE CORROSION BRIDGING ACROSS COPPER TRACKS, CREATING 2 SHORT CIRCUITS.