LTT COMMUTER HAS TCASII RA. RESPONDS AFTER NOTIFYING ATC. FALSE TARGET.

Narrative

DURING A SCHEDULED FLT FROM BWI TO BOS; WE WERE AT FL210. IT WAS THE CAPT'S LEG. ATC CALLED TFC 11-12 O'CLOCK AT FL240 DSNDING TO FL220. WE PICKED UP THE TARGET ON TCASII BUT NOT VISUALLY. IT WAS HAZY AT OUR ALT. THEN A TARGET APPEARED ON TCASII AT FL210 AT 12 O'CLOCK. THIS WAS FOLLOWED BY AN RA INSTRUCTING US TO CLB. INDICATING A RATE OF ASCENT OF 3000 FPM. WE IMMEDIATELY TOLD ATC OF OUR SITUATION AND THE TCASII ALERT; THEN BEGAN A CLB. THE TFC AT 12 O'CLOCK THAT INDICATED FL240 WAS PASSING OFF OUR L. WE STILL HAD A GOOD SIGNAL FROM HIM. ATC ALSO STOPPED THAT ACFT FROM DSNDING. THE TFC THAT GAVE US THE RA CLRED US. ATC NEVER PAINTED HIM. THEY TOLD US THAT THEY WOULD FILE A TCASII RPT. IT SHOULD NOT AFFECT US. MY BELIEF IS THAT THE TCASII PROGRAM SHOULD BE REFINED AND TESTED MORE BEFORE FORCING THE CREWS TO RESPOND. IN THIS SITUATION MORE LIKELY THAN NOT IT WAS A GHOST TARGET. ATC NEVER PAINTED HIM NEITHER CREW MEMBER HAD A VISUAL OR HAVE BETTER MORE DEFINED GUIDELINES ON SITUATIONS LIKE THIS. I CANNOT AFFORD TO HAVE MY LICENSE SUSPENDED OVER A 'GLITCH' WITH THE SYS.