As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AT GATE CONNECTED TO GROUND POWER, SMOKE STARTED TO FILL CABIN. (FLT 6207) INSPECTED CABIN, NO SMOKE FOUND. NO SMELL OF SMOKE FOUND. RAN AIRCRAFT ELECTRICAL SYSTEMS WITH GROUND POWER FOR SEVERAL HOURS IN THE HANGAR WITH NO VISIBLE SMOKE NOTED.