What was found
DURING FLIGHT 3021/3022/3092 MAIN DOOR HANDLE CAUTION LIGHT W/DOOR INDEX THAT DID NOT LINE UP. AIR RETURN TO MSP. MAINTENANCE PRESSURIZED AIRCRAFT & COULD NOT DUPLICATE PROBLEM. CLEANED & LUBRICATED INTERNAL HANDLE GEAR SEGMENT & PINION. PERFORMED OPS TEST OF PAX DOOR IAW AMM 52-10-00. OPS TEST GOOD. PERFORMED MAIN DOOR WARNING OPS TEST IAW AMM 52-70-00. OPS TEST GOOD. VERIFIED CORRECT POSITIONING OF ALIGNMENT MARKS WITH HANDLE IN CLOSED POSITION.