AERO COMMANDER; AC11 PLT TURNED BASE TOO EARLY IN FRONT OF A CESSNA ON FINAL DUE TO MISUNDERSTANDING OF THE ACFT TO FOLLOW BY APCH CTLR. THE TWR CTLR NOTICED THE PROB AND REDIRECTED HIM BEHIND THE ACFT ON FINAL.

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ON APCH TO ADDISON; DFW REGIONAL APCH INSTRUCTED ME TO ENTER DOWNWIND. APCH INDICATED 2 CESSNA ACFT ON FINAL. I INDICATED I HAD VISUAL ON ONE CESSNA ACFT; ON VERY SHORT FINAL (NEAR THRESHOLD); BUT NOT THE OTHER. I THEN SAW A SECOND CESSNA ACFT ON 2-3 MI FINAL AND ADVISED APCH. APCH CLRED ME TO FOLLOW THAT ACFT; AND CLRED ME FOR THE VISUAL APCH. NO MENTION WAS MADE OF OTHER ACFT. I BEGAN A BASE TURN BEHIND THE SECOND ACFT AND SWITCHED TO TWR. TWR IMMEDIATELY ADVISED ME THAT I SHOULD HAVE BEEN ON DOWNWIND; THAT THERE WAS ANOTHER ACFT ON APCH. I ADVISED THAT I WAS CLRED FOR THE VISUAL BEHIND THE CESSNA. TWR INSTRUCTED ME TO FLY THROUGH THE FINAL APCH COURSE FOR A 180 DEG TURN; THE THIRD CESSNA HAD ME IN SIGHT. TWR THEN BROUGHT ME AROUND FOR LNDG. THIS WAS A CASE OF MISCOM. I WAS NOT AWARE OF THE THIRD ACFT; OR APCH WAS NOT AWARE OF THE AIRPLANE ON SHORT FINAL. IN ANY EVENT; FROM MY VIEWPOINT; THERE WERE REALLY 3 ACFT; NOT 2; AND I PLACED TOO MUCH RELIANCE IN ATC'S TFC ADVICE IN THE BUSY TERMINAL ENVIRONMENT. I THOUGHT I COMMUNICATED WELL WHEN I INDICATED THAT I SAW A PLANE ON SHORT FINAL; BUT APPARENTLY THERE WAS SOME CONFUSION AS TO THE EXACT NUMBER OF ACFT IN THE PATTERN. IT WOULD HAVE HELPED IF APCH HAD SWITCHED ME TO TWR AS I ENTERED THE DOWNWIND (SO TWR COULD SORT IT OUT AND SEQUENCE PLANES); OR IF APCH HAD INDICATED THE DISTANCE FROM THE RWY FOR EACH OF THE OTHER ACFT. IF THAT HAD BEEN DONE; I WOULD HAVE KNOWN -- FOR CERTAIN -- THAT THE PLANE I SAW ON SHORT FINAL WAS NOT THE SAME PLANE THAT APCH WAS DISCUSSING ON FINAL. ALTERNATIVELY; APCH OR TWR COULD HAVE CALLED MY BASE. IN ADDITION; THE CESSNA INVOLVED IN THE NEAR MISS DID NOT HAVE ITS LNDG LIGHT ON; MAKING IT HARDER TO SEE. USE OF LNDG LIGHTS HELPS RECOGNITION IN A CROWDED PATTERN. WHILE IT'S GREAT TO HAVE LANDED SAFELY; BETTER COM COULD HELP AVOID THIS ISSUE NEXT TIME.