What was found
CREW REST, SMOKE MAIN LIGHT ILLUMINATED FOR APPROXIMATELY 20 SECONDS WHEN FIRST LEVEL OFF DURING CRUISE. FLIGHT ATTENDANT REPORTED ELECTRICAL ODOR WHICH QUICKLY DISSIPATED. AIRCRAFT WAS IN NORMAL CONFIGURATION. THE AIRCRAFT WAS GROUNDED. MAINTENANCE ACCOMPLISHED MCM 05-96-70, VERIFIED THE SMOKE ODOR AND REPLACED MDCR HEATER ASSEMBLY IAW AMM 21-41-30 AND PERFORMED SATISFACTORY OPERATIONAL CHECK, NO ODOR NOTED.