What was found
WHILE IN DESCENT IN HEAVY PRECIPITATION TO HOME BASE, MASTER CAUTION ILLUMINATED, SMOKE IN BAGGAGE. THE PIC DECLARED AN EMERGENCY AND DESCENDED INTO PIT. THE AIRCRAFT WAS EXAMINED BY THE FIRE CREW THERMAL IMAGING AND NO HOT SPOTS OR SMOKE WAS FOUND, WARNING WAS NOT PRESENT. THE PIC CONDUCTED THE PRE-FLIGHT CHECKS WITH NO FAULTS FOUND. THE AIRCRAFT WAS POWERED UP AND DOWN SEVERAL TIMES WITH NO INDICATIONS OR FAULTS FOUND. BAGGAGE COMPARTMENT SMOKE DETECTION FUNCTIONAL CHECK 26-11-00 PERFORMED IAW MM REQUIREMENTS WITH NO FAULTS. VISUAL INSPECTION OF BAGGAGE COMPARTMENTS AND SMOKE DETECTORS FOUND NO DEBRIS, CONTAMINATES OR OBVIOUS ABNORMALITIES. TALKING WITH MANUFACTURES TECHNICAL SUPPORT TEAM IT WAS DISCUSSED THAT THE HEAVY PRECIPITATION MAY HAVE CAUSED THE FALSE INDICATION.