What was found
RIGHT AFT ENTRY DOOR EICAS MESSAGE DURING TAXI CYCLES ON AND OFF. WHEN HANDLE IS CLOSED AND IT STILL JIGGLES A LITTLE, RIGHT AFT ENTRY DOOR EICAS MESSAGE IS DISPLAYED & OVERHEAD ENTRY DOOR LIGHT IS ILLUMINATED. WHEN HANDLE IS CLOSED HARD, WITH NO LOOSENESS, NO MESSAGES & LIGHT. OPS CHECK OF R4 DOOR SENSOR SWITCH OK. FOUND SENSOR TARGET NUT BACKED OFF WITH TOO MUCH AIR GAP TO SENSOR WHEN DOOR CLOSED. TIGHTENED NUT AND CHECKED AIR GAP. OPS CHECK GOOD IAW AMM.