As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE IN CRUISE AT FL380, THE LT GEN ANNUNCIATOR ILLUMINATED. AT THE SAME TIME, AUTOPILOT DISCONNECTED AND BELL/ANNUNCIATOR ILLUMINATED. FOLLOWED BY SIGNIFICANT ELECTRICAL SMOKE AND FUMES FROM BEHIND THE INSTRUMENT PANEL. AFTER TROUBLESHOOTING, FOUND THE CABIN ACFT ELECTRICAL OUTLET INVERTER LOCATED UNDERNEATH THE COPILOT'S SEAT HAD SHORTED INTERNALLY CAUSING THE SMOKE.