if I am subpoenaed as a witness/victim for family violence but do not wish to go, what can happen to me if I do not show?

Most of the time the prosecutor will mail the subpoena.  In most states, this is not proper.  In order for a subpoena to be lawful it has to be served properly.  Check the local court rules to ensure the subpoean has been proberly served.

That said, your subpoena will usually tell you the potential penalties that you could face by ignoring it.  Of course, the prosecutor may just dismiss the case and you will never here about it again.

However, you do face the potential penalties if you ignore a lawful subpoena.  Lawful subpoena is the question.

Hope this helps