ATCT LCL CTLR MIXES UP CALL SIGNS.

Narrative

SITUATION BEGAN ON A ROUTINE VFR PLEASURE FLT INTO LUK ARPT. ONBOARD ACFT WERE MYSELF; AN ATC SPECIALIST STATION WITH A COMMERCIAL CERTIFICATE AND INSTRUMENT RATING AND THE COPLT AEFII/MEI. AT 10 MI NE OF THE ARPT WE MADE THE INITIAL CALL UP WITH THE TWR. WE WERE INSTRUCTED TO FLY STRAIGHT IN TO RWY 20L AND RPT A 3 MI FINAL. AT 6 MI OUT THE LCL CTLR WAS WORKING ABOUT 5-6 ACFT ON 2 PARALLEL RWYS. AT THIS TIME THE CTLR ASKED AN ACFT WITH A CALL SIGN CLOSE TO OURS TO IDENT ON THE TRANSPONDER. I HEARD THE CTLR IMMEDIATELY START TALKING TO ANOTHER ACFT SO I ASSUMED THAT THE INSTRUCTIONS WERE FOR THAT ACFT. AGAIN THE CTLR ASKED THE ACFT WITH CLOSE CALL SIGN TO DO SOMETHING; AND I ASKED IF THE INSTRUCTION WAS FOR ME. AGAIN THE CTLR STARTED TO TALK TO ANOTHER ACFT. THEN THE CTLR ASKED US; USING WRONG TAIL NUMBER; TO SWITCH TO RWY 20R. AT THAT TIME I AGAIN ASKED IF THESE INSTRUCTIONS WERE FOR US. THIS TIME HE UNDERSTOOD ME AND REALIZED HE WAS USING THE WRONG CALL SIGN AND ASKED ME TO SWITCH TO RWY 20R. OVER THE NUMBERS FOR 20R I HAD TO ASK FOR LNDG CLRNC WHICH WAS RECEIVED. EVEN THOUGH NO MIDAIR OR VIOLATION TOOK PLACE; THIS SITUATION COULD HAVE DEVELOPED INTO AN INCIDENT. THE CTLR DID NOT WAIT FOR A REPLY OR ACKNOWLEDGEMENT TO HIS INSTRUCTIONS AND DID NOT HEAR WHAT WAS BEING SAID; BUT HEARD WHAT HE EXPECTED TO HEAR! ALL PLTS AND CTLRS MUST BE MADE AWARE TO LISTEN FOR A CORRECT REPLY AND AN ACTION TAKEN BY THE ONE RECEIVING THE INSTRUCTION. IF THE SITUATION CONTINUES TO DEVELOP; TAKE ACTION AND DETERMINE THE PROB. IN THIS CASE ALL THE CTLR HAD TO DO IS ASK; 'ACFT INSTRUCTED TO RPT 3 MI FINAL 20L SAY NUMBERS.' WITH THIS INFO HE COULD HAVE EASILY HAVE CTLED THE SITUATION BY MAKING CERTAIN OF THE ACFT HE NEEDED TO COMMUNICATE WITH WAS US.