As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PILOT REPORTED SMOKE IN THE COCKPIT CLIMBING OUT OR A NIGHT VFR FLIGHT. INSPECTED AIRCRAFT AND FOUND NAV LIGHT / INSTRUMENT LIGHT SWITCH / RHEOSTAT HAD OVERHEATED. ORDERED REPLACMENT SWITCH (PN 587779) AND INSTALLED. OPS CHECKS GOOD. I HAVE SEEN THESE RHEOSTATS GET HOT BEFORE.