What was found
AFTER DEPARTURE FROM KDOV, THE TOWER ADVISED THE CREW THAT THEY WERE TRAILING SMOKE. SOON AFTER, THE CARGO FIRE LIGHT ILLUMINATED. THE AIRCRAFT RETURNED TO KDOV. THE TRAILING SMOKE IS SUSPECTED TO HAVE BEEN WATER VAPORS DUE TO THE AIRCRAFT SITTING IN THE RAIN SEVERAL DAYS. THE SMOKE DETECT LIGHT ILLUMINATING WAS FALSE INDICATION. NO SMELL OF SMOKE OR EVIDENCE OF FIRE WAS FOUND. MAINTENANCE PERSONNEL FOUND FAULTY SMOKE DETECTION BOX. SMOKE DETECTOR WAS REPLACED WITH SERVICEABLE UNIT. PERFORMED OPERATIONAL CHECKS.