My wife was served a summons on a credit card debt. I am not on her account. They served her and added "Husband Joe Doe" to summons. What do I have to do, she doesn't intend to answer.

If she doesn't intend to answer, that's a pretty good indication of how she got herself into this mess.

If she doesn't show up for court, a default judgment will be entered against her. If you don't contest that your name was not on the account and prove you didn't use the account, the judgment may also go against you as well.

In most states, the creditor/plaintiff can then file a lien against anything with your name(s) on it.