As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED ODOR IN COCKPIT. INTIALLY SUSPECTED HEATER, BUT ODOR REMAINED AFTER HEATER WAS TURNED OFF. CREW NOTICED SMOKE COMING FROM INSTRUMENT PANEL LIGHTING SWITCH. TURNED OFF SWITCH, SMOKE STOPPED, LANDED WITHOUT INCIDENT. MX R & R INSTRUMENT PANEL DIMMER ASSY. ACFT RELEASED BACK TO SERVICE.