Your question sounds like a made-for-television movie! But it is all to familiar to those of us practicing in Baltimore City/County. Any lawyer you consult will ask for copies of your father's divorce decree/separation agreement with his ex-wife, the current recorded title documents (deed, and deed of trust), and your father's probate documents (what has been filed to adminster his estate). These are the documents that will allow us to tell you whether you and your brother have any ownership interest, whether the house is subject to probate, and whether the ex-wife has any interest in the property. Any other answers you get on this site will be guesswork that may steer you deeper into the weeds.
I agree with Attorney Valkenet's analysis and conclusion. There is no way to answer your questions without the information indicated. You also need to have a lawyer to assist you in sorting this out. Trying to go without one could literally cost you the house. I would suggest you contact Attorney Valkenet.
***Please be sure to mark if you find the answer "helpful" or a "best" answer. Thank you! I hope this helps. ***************************************** LEGAL DISCLAIMER I am licensed to practice law in the State of Michigan and have offices in Wayne and Ingham Counties. My practice is focused in the areas of estate planning and probate administration. I am ethically required to state that the above answer does not create an attorney/client relationship. These responses should be considered general legal education and are intended to provide general information about the question asked. Frequently, the question does not include important facts that, if known, could significantly change the answer. Information provided on this site should not be used as a substitute for competent legal advice from a licensed attorney that practices in your state. The law changes frequently and varies from state to state. If I refer to your state's laws, you should not rely on what I say; I just did a quick Internet search and found something that looked relevant that I hoped you would find helpful. You should verify and confirm any information provided with an attorney licensed in your state. I hope you our answer helpful!
Just to add to Mr. Valkenet's excellent answer: ASSUMING that your father and his ex-wife did not provide otherwise as part of their divorce proceeding (a mighty big assumption), then upon divorce the law automatically converts titled ownership of real property from Tenants by the Entireties (a joint ownership by husband and wife), to Tenants in Common (TC). A TC ownership interest in your scenario would result in a 50% ownership of the property by your late father, which would pass to his heirs (you and your brother, if you are the only two heirs at law and there really is no will). The other 50% would be owned by the ex-wife. One of you two children needs to open an estate, ASAP, for your father, and list the estate's interest in the property. Both the estate and the ex-wife have legal rights to the property. You need to have a Personal Representative appointed before the estate can do anything regarding the property, and only the estate has the legal right to act. Therefore, hire an estate/probate lawyer up in Baltimore (Mr. Valkenet immediately comes to mind), and get cracking on this. At once.