I got court papers to appear in court but my ex's attorney put me as the plaintiff and my ex as the defendant. what can I do sense it's wrong?

It's possible that a different procedure is followed in Tennessee, but in the states in whch I practice, contempt proceedings are generally initiated in the context of an existing lawsuit.  For example, if one party (plaintiff or defendant) fails to comply with a court order, the other side will make a motion to hold the non-compliant party in contempt.  It could well be that the defendant is the movant seeking to hold the plaintiff in contempt.  For example, you, plaintiff, sue your ex, defendant, for divorce.  In that proceeding, the Court orders you to pay your ex $100 per week for child support for the next 10 years.  Three years later, your ex claims that you violated this order.  Your ex would, under the docket number of the original divorce proceeding, in which you are the plaintiff and your ex is the defendant, make a motion to hold you in contempt.