What was found
GFK/BIS, FLT 8563 - EN ROUTE PILOT DETECTED FAINT SMELL OF SMOKE FROM AN ELECTRICAL SOURCE. NO CIRCUIT BREAKERS OPENED, NO EQUIPMENT OR SYSTEM FAILURES. ALL NON-ESSENTIAL ELECTRIC POWER WAS SECURED. AIRCRAFT LANDED WITHOUT INCIDENT. CRASH, FIRE AND RESCUE MET AIRCRAFT AT RUNWAY. NO CAUSE OF PROBLEM/SOURCE OF SMOKE SMELL IDENTIFIED. AIRCRAFT WAS INSPECTED, GROUND RUN-UP AND ALL SYSTEMS CHECKED WITH NO DEFECTS NOTED. A TEST FLIGHT PERFORMED WITH NO DEFECTS NOTED. NO FURTHER SMELL OF SMOKE. AIRCRAFT WAS RETURNED TO SERVICE.