What was found
ODOR OF BURNING INSULATION DETECTED IN CABIN. NO SMOKE PRESENT. CHECKED FOR TRIPPED CIRCUIT BREAKERS. NONE FOUND. RECYCLED/RESET BOTH GENERATORS TO CHECK LOAD ON EACH. NO PROBLEMS DETECTED AND RESTORED BOTH GENERATORS. CONTINUED TO FINAL LANDING AT BASE AND TURNED AIRCRAFT OVER TO MECHANIC FOR TROUBLESHOOTING. AIRCRAFT OPERATED ON GROUND WITH BOTH ENGINES RUNNING AND BOTH GENERATORS OPERATING IN A ELECTRICALLY LOADED CONDITION. NO ODOR NOTED, SYSTEMS OPERATED NORMALLY. OPERATED ELECTRICAL/ AVIONICS USING GROUND POWER FOR GREATER THAN ONE HOUR, NO ODOR NOTED. CABIN CEILING LIGHTS FOUND INOPERATIVE. FOUND CABIN LIGHT RELAY IN A FAILED CONDITION. DEACTIVATED CABIN LIGHTS IAW MEL. NEW RELAY ON ORDER.