What was found
AFTER TAKEOFF ON GEAR RETRACTION, RECEIVED A RIGHT MAIN GEAR LIGHT INDICATING RED, AND CONFIGURATION CUE RIGHT MAIN GEAR INDICATED RED. FOLLOWED QRH, RECYCLED GEAR DOWN AND BACK UP, SAME INDICATIONS, RIGHT MAIN RED. RETURNED TO DEPARTURE, ALL GEAR INDICATIONS NORMAL FOR LANDING. FOUND DOOR PROXIMITY SENSOR GAP TOO CLOSE, ADJUSTED THE SENSOR GAP IAW MM 32-34-03-2. SWUNG GEAR SEVERAL TIMES, INDICATION CHECKS GOOD.