What was found
FLT 7537 IAD DAY LAV SMOKE ILLUMINATED IN FLIGHT, CREW FOLLOWED QRH PROCEDURES. FLIGHT ATTENDANT NOTICED NO DESCREPENCIES, SENT MECHANIC FROM FWA TO MEET A/C INSPECTED LAV, NO DEFECTS NOTED DEFERRED LAV SMOKE SYSTEM PER MEL 26-13-1. FOLLOWED MAIN/OPS PROCEDURES, A/C FLOWN PART 91 TO FWA.