How many cogs on your current cassette? Do you in fact have a cassette-based system, and not a freewheel? Finally, what is the brand of the rear hub and the cogs - which might not be Campagnolo.
Without this critical information, you're going to get pages of misleading and irrelevant discussion.
Such as for example, suggestion to slap on the common 13-29 10-speed cassette. Of course, this would require a complete drivetrain changeover, involving shifters, derailleurs and a new rear wheel. So at least $500 of new parts and $150+ of shop time.
If you have a 8-speed rear Campy hub, then no, it won't fit a 9,10 or 11 speed cassette.
OTOH, you may be able to fix your problem for less than $5. More info required from you...
Last edited by Dave Mayer; 09-02-17 at 01:35 PM.