What was found
MLG WOULD NOT RETRACT AFTER TAKEOFF. VISUALLY INSPECTED MLG SYS & FOUND NO DAMAGE. JACKED ACFT. PILOT CONFIRMED THAT 3 GREEN LIGHTS REMAINED ON, TRANSIT/WARMING LIGHT DID NOT ILLUMINATE & MLG HORN SOUNDED. EXPOSED SQUAT SWITCH WIRING SPLICES & TESTED SWITCH OPERATION. SWITCH FUNCTIONED NORMALLY. FOUND GROUND WIRE 1-20 MOUNTING HARDWARE LOOSE. TIGHTENED HARDWARE. CONNECTED HYD POWER SUPPLY TO ACFT & ATTEMPTED GEAR SWING. MLG WOULD NOT RETRACT. PUT MLG HANDLE IN DOWN POSITION & MANUALLY CYCLED MLG SWITCH. PUT MLG HANDLE IN UP POSITION & APPLIED HYD POWER, MLG RETRACTED NORMALLY. EXTENDED MLG & REMOVED SQUAT SWITCH FROM STRUT. CONNECTED MULTIMETER TO SWITCH & CYCLED BOTH SIDES OF SWITCH SEVERAL TIMES WITHOUT DEFECT. REINSTALLED SWITCH & RIGGED IAW MM. PERFORMED 3 NORMAL MLG RETRACTIONS. LOWERED ACFT TO ACTUATE SQUAT SWITCH & JACKED AGAIN. CYCLED MLG 3 MORE TIMES WITHOUT INCIDENT.