What was found
LANDED, PROCEEDED WITH NORMAL SHUTDOWN PROCEDURES. DURING TWO-MINUTE SHUTDOWN, NOTICED GENERATOR CYCLING ON AND OFF, FIRE LIGHT ILLUMINATED MOMENTARILY THEN WENT OUT. FIRE LIGHT CAME ON AGAIN WITH MORE GENERATOR CYCLING. EXITED HELICOPTER WITH ENGINE AT FLIGHT IDLE AND LOOKED IN ENGINE COMPARTMENT. SAW 8 INCH FLAMES FROM GENERATOR CONNECTOR PLUG IN ENGINE DECK. SHUT DOWN ENGINE IMMEDIATELY. GOT HAND HELD EXTINGUISHER, OPENED ENGINE COWL AND EXTINGUISHED FIRE. SAW SMOKE COMING FROM OTHER AREAS OF THE HELICOPTER. OPENED OTHER ACCESS PANELS AND LOOKED FOR MORE FIRE. SHOT EXTINGUISHER INTO THE SIGHT HOLE IN RIGHT SIDE OF AIRCRAFT, UNDER ENGINE DECK, TO HIT BOTTOM SIDE OF GENERATOR CONNECTOR PLUG.