As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) FLIGHT CREW OBSERVED SMOKE IN CABIN. ACFT RETURNED TO BASE. MX WAS CALLED AND UPON INSP FOUND EXCESSIVE OIL IN UNIT AND OIL SMEARED AROUND THE PANEL BY THE AIR CYCLE MACHINE. THE OIL LEVEL WAS ADJUSTED AND THE EXCESS AMOUNT WAS REMOVED. ACFT GROUND TESTS SERVICEABLE AND RETURNED TO SERVICE.