As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER THE FLIGHT CREW DEPARTED MKE ON FLT NR 1157 FOR MSN, FOUND THAT THE CARGO DOOR ANNUNCIATOR ILLUMINATED IN FLIGHT AND DECIDED TO RETURN TO MKE, MEL'D THE CARGO DOOR ANNUNCIATOR SYSTEM 52-2 CAT C. MAINTENANCE LATER FOUND A LOOSE TERMINAL SCREW ON A MICROSWITCH, TIGHTENED IT AND OPERATIONAL CHECKED NUMEROUS TIMES. (M)