Child support

Ok, here is my situation: My ex spouse and I was divorced about 6 months ago and the court order states that neither of us pay child support. She is an RN that is unemployed at her own will. I am employed as well. I have been recently contacted by a private firm that apperently goes after child support from parents that do not pay. They sent me a letter (via mail) asking for my ssn and recent pay stubs with a NC statute at the bottom. By the name of the company it appears they are affiliated with the state of NC. I called them to find out if they were in fact affiliated with the state and they claimed they were not. They said they would review my case (which I do not have one) where my ex spouse had came to them and get back with me. They did not. Now they are contacting my employer (via mail )and demanding my last 4 pay stubs and my ssn with the same NC statute at the bottom of there letter. My employer is adimant about having to send them what they are requesting. So my question is this: Number 1, do they have to send my confidential pay stubs to this private firm that is not affiliated with the state of NC?, and Number 2, do I need to be worried or need to get my attorney back involved? It appears she is trying to go after me for child support and just cannot afford an attorney. Thank you in advanced!!

P.S. I have legal 50% custody of the children per my court order.