What was found
FLT 7559 - FMN-DEN - IN FLIGHT THE CREW NOTICED THE CARGO DOOR ANNUNCIATOR HAD ILLUMINATED. THE AIRCRAFT DIVERTED TO GUC AND LANDED WITH NO FURTHER INCIDENT. THE CARGO DOOR WAS INSPECTED BY THE CREW AND FOUND TO BE CLOSED AND LATCHED. MAINTENANCE CONTROL DEFERRED THE ANNUNCIATOR SYSTEM PER MEL 52-2. AIRCRAFT WAS RETURNED TO SERVICE. IN SUBSEQUENT MAINTENANCE, THE MICROSWITCH WAS RIGGED, OPS CHECK GOOD. (M)