Only a court or an attorney can issue a subpoena. If you are representing yourself then you have to go through the court. Aside from the procedures, there are problems you need to consider:
1. If the house is still community property, as you stated, you are entitled to half of the rent, if any.
2. If there is rental income, then tax form should show. If your ex never reported this income, then where you came with the idea that there was rental income?
3. If you subpoena the tenant, he or she can move to quash. In addition, you have to pay for all the expenses associated with the subpoena, including the appearance by the tenant in court.
