WRONG ARPT APCH IN A NIGHT OP.

Narrative

ON A NIGHT DSCNT TO TERMINAL AREA I WAS ON A HDG (150 DEGS) DIRECT TO SHV UNDER ATC RADAR SVC. WHEN CHANGED OVER TO APCH CTL; THE CTLR SAID OUR HDG WAS GOOD FOR OUR DEST ARPT. WE WERE CLRED TO 3000 FT. BEING AWARE OF PROX OF BARKSDALE AFB AND HAVING IT IN SIGHT TO MY L I BEGAN LOOKING FOR VISUAL CONTACT WITH SHV. WE WERE ON A HDG OF APPROX 150 DEGS. THE FO CALLED OUT THAT HE HAD THE ARPT BEACON IN SIGHT AND POINTED IT OUT TO ME. I GOT IT IN SIGHT AND KEPT IT IN SIGHT AS WE PROCEEDED INBOUND ON A DOWNWIND HDG. WHEN CLOSER ABEAM I COULD DETERMINE THE ARPT RWY LAYOUT AND CONFIRMED THE LAYOUT WITH THE ARPT DIAGRAM FOR SHV REGIONAL ARPT. WE TOLD APCH CTL WE HAD ARPT IN SIGHT AND WERE CLRED FOR A VISUAL APCH; BUT NOT TOLD TO SWITCH TO TWR FREQ. AS WE ROLLED OUT ON FINAL I OBSERVED OUR INST COMPARATOR LIGHTS BOTH (CAPT/FO) CAME ON AND THAT OUR NDB BEARING WAS ABOUT 40 DEGS L. IT SHOULD HAVE BEEN INDICATING DEAD AHEAD; IF WE HAD BEEN ON APCH TO RWY 32. THE NDB IS ON THE APCH COURSE FOR RWY 14 AT SHV. I REALIZED WE WERE LINED UP ON A RWY AT THE WRONG ARPT. SHREVEPORT DOWNTOWN HAS AN IDENTICAL RWY LAYOUT AS REGIONAL. I WAS JUST INITIATING A GAR WHEN APCH CTL TOLD US WE WERE LINED UP ON RWY 32 AT DOWNTOWN AND GAVE US VECTORS TO TURN L AND ENTER DOWNWIND FOR LNDG RWY 32 REGIONAL.