MLG CREW HAD APU FIRE WARNING.

Narrative

ON FINAL APCH TO RWY 18L AT MCO THE APU FIRE WARNING LIGHT ILLUMINATED AND THE FIRE BELL SOUNDED. THE FIRE HANDLE WAS PULLED AND ROTATED TO DISCHARGE THE FIRE BOTTLE. THE LIGHT REMAINED ILLUMINATED BUT THERE WAS NO OTHER INDICATION OF A FIRE. WE LANDED; CLRED THE RWY AND TAXIED IMMEDIATELY TO THE GATE WHERE THE ONCOMING CREW WAS WAITING. WE RAN THE CHKLIST DURING THE SHORT TAXI. THE ONCOMING FO GAVE NO INDICATION OF ANYTHING IRREGULAR AND THE CAPT IMMEDIATELY LEFT THE ACFT TO INSPECT THE APU AREA. ALL APPEARED NORMAL. CAPT CALLED DISPATCH; DUTY CTL AND CONTRACT MAINT. WE BELIEVED THIS TO BE THE SAFEST ACTION TO TAKE BEING IT WAS ALL 'LAST MIN' IN THE FLT AND RWY WAS CLOSE TO THE GATE. THE APU WAS NOT RUNNING AND HAD BEEN OFF ABOUT 1 HR 45 MINS PRIOR TO THE FIRE WARNING WITH NO ATTEMPTED RESTART. WE PLUGGED GND PWR IN AT THE GATE. LOOKING BACK AT THIS EVENT; BEING IT ALL CAME TOGETHER IN THE LAST FEW MINS OF THE FLT; WE OVERLOOKED TELLING TWR OF WHAT WAS GOING ON AND TO DECLARE AN EMER AND TO CALL THE FIRE TRUCKS. IT WAS A FALSE INDICATION. NEXT TIME SLOW DOWN GETTING ACFT TO THE GATE TO MAKE SURE YOU HAVE THE 'LITTLE' THINGS DONE ALSO AND TO NOTIFY PEOPLE DURING THE EVENT; NOT AFTER.