What was found
AIRCRAFT WAS GROUNDED: WHILE AT CRUISE FLIGHT ATTENDANTS REPORTED SMOKE COMING FROM SEAT ROW 18 RIGHT. CREW FOLLOWED QRH PROCEDURE AND THE SMOKE STOPPED. AN EMERGENCY WAS DECLARED AND THE AIRCRAFT DIVERTED TO MSN WHERE IT LANDED SAFELY WITHOUT FURTHER INCIDENT. INITIAL TROUBLESHOOTING INDICATES THE IN FLIGHT ENTERTAINMENT SYSTEM IS THE CAUSE OF THE ISSUE. FOUND SEAT ELECTRONIC BOX AT SEAT ROW 18 TO BE THE CAUSE OF THE ODOR. REPLACED SEAT ELECTRONIC BOX AND ACCOMPLISHED A SATISFACTORY OPERATIONAL CHECK PER AMM 44-24-32.