You have been subpoenaed. Your options are to contact the law firm that issued the subpoena to try to convince them that you're the wrong "Joe Smith", to file a motion to quash with the court seeking relief before the deadline set by the subpoena, to comply, or to ignore the subpoena and risk monetary sanctions (very likely to be awarded to the other party), possible contempt proceedings and, depending upon the full context, a possible bench warrant for your arrest.