ACR X APCH TO WRONG RWY RECEIVED TCASII TA RA CLB EVASIVE ACTION TAKEN HAD CONFLICT WITH ACFT Y.

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ACR X HAD PLANNED AN ILS TO RWY 19L AND HAD ARMED THE LOC FOR CAPTURE. ABOUT 1-2 MINS BEFORE TA WE WERE RECLRED FOR VISUAL TO RWY 19R. BOTH OF US FAILED TO REMEMBER TO DESELECT THE RWY 19L LOC AND PROCEEDED TO LINE UP FOR RWY 19L. SHORTLY THEREAFTER THE TA/RA SOUNDED AND WE IMMEDIATELY ASKED FOR CONFIRMATION ON RWY TO WHICH WE WERE CLRED. TWR CTLR CONFIRMED RWY 19R AND INDICATED WE HAD TFC BEHIND US AND BELOW. WE HAD PULLED UP ON RESPONSE TO THE RA AND THEN PULLED OVER TO ALIGN WITH RWY 19R. SUPPLEMENTAL INFO FROM ACN 200970. WHILE ON INTERCEPT HDG FOR ILS RWY 19L; TRACON RECLRED US FOR VISUAL RWY 19R. I MISINTERPRETED CLRNC FOR VISUAL RWY 19L AND CONTINUED TO INTERCEPT AND FLY LOC. WHILE DSNDING 1500 FT ABOVE GS; WE GOT TCASII TA FOLLOWED BY RA. I INITIATED CLB THEN LEVEL OFF WHILE CAPT ADVISED TWR AND ASKED FOR CONFIRMATION OF RWY. WE SUBSEQUENTLY SIDE STEPPED TO 19R AND COMPLETED NORMAL APCH AND LNDG. TWR ADVISED TFC FOR 19L THAT WE WERE ABOVE AND AHEAD. THEY RPTED US IN SIGHT 'HIGH.' IT IS EASY TO OVERLOOK A SUBTLE CLRNC CHANGE IN THE BUSY APCH ENVIRONMENT '1000 FT' CALL OUT IS SUPPOSED TO BREAK THIS CHAIN; BUT THAT WOULD HAVE BEEN TO LATE UNDER THESE CIRCUMSTANCES. I WILL DEVELOP A PERSONAL HABIT TO RESOLVE THIS AMBIGUITY AT LOC/CTRLINE INTERCEPT.