What was found
N227MC WAS EN-ROUTE FROM RYY-BNA EMPTY FOR A CHARTER TRIP, AND THE CREW NOTED SMOKE IN THE CABIN. AN EMERGENCY WAS DECLARED, AND THEY DIVERTED TO DALTON, GA. AIRCRAFT LANDED WITH OUT INCIDENT. UPON INVESTIGATION BY CESSNA, IT WAS DISCOVERED THE ROOT CAUSE OF THE ISSUE WAS FROM THE APU BLEED AIR SYSTEM. VERIFIED BY RUNNING THE APU BLEED. SMELL IMMEDIATELY NOTED. SHUT DOWN APU AND RAN ENGINES WITH BLEED AIR ON. NO SMELL NOTED. CAUSE OF APU FAILURE NOT KNOWN AT THIS TIME. TROUBLESHOOTING WILL BEGIN TOMORROW 11/15.