I've never looked inside one of these, but in my limited experience of repairing electronic stuff, generally any capacitor that is rated for the voltage you have and is close to the microfarad rating (within 20% or so) will often work fine. Can you read the values on the cap you have? Is it sodered in or have legs that are bolted on? There are some guys on this board that really know this stuff...maybe they will pitch in here.
Good Luck