What was found
LOG PAGE 028581. AIR RETURN. AFTER TAKEOFF, GEAR RETRACTED. LEFT MAIN LANDING GEAR INDICATED DOWN WITH NO RED (UNSAFE) LIGHT. DOOR LIGHT WAS OUT. GEAR INDICATION NORMAL, LANDING NORMAL. CORRECTIVE ACTION: FOUND MINOR CORROSION IN LEFT MAIN GEAR DOWNLOCK SWITCH CONNECTOR. CLEANED CORROSION, SWUNG GEAR IAW DC-9MM, CHAPTER 32-60-0, 4 TIMES, OPS CHECKED GOOD. (X)