What was found
THE CABIN DOOR WARNING ANNUNCIATOR ILLUMINATED IN FLIGHT, THE LIGHT EXTINGUISHED WHEN THE CABIN DIFFERENTIAL PRESSURE DROPPED TO 1.0 PSI. THE CREW DIVERTED TO SBN FROM THE INTENDED DESTINATION OF MKE, FLIGHT NR 1053.1. THE AIRCRAFT WAS THEN FERRIED FROM SBN TO MKE. MAINTENANCE CLEANED AND LUBED THE SENSE SWITCH. THEY ALSO TIGHTENED A LOOSE WIRE TERMINAL TO THE SWITCH. OPERATIONALLY CHECKED THE SYSTEM AND FOUND NORMAL. (X)