Legal Question in Real Estate Law in California

Your very brief question raises a number of questions regarding the surrounding facts that an attorney would need answered in order to give you a well-reasoned answer. The flip answer is that you can sue (almost) anyone for (almost) anything, but what are your chances of success?

A more serious answer is that any suit for breach of contract must begin by pleading the existence of a contract, its terms, and a breach thereof by the defendant. Generally, contracts regarding real estate need to be in writing, although there are numerous exceptions -- was there a written contract agreed to and signed by the ex-wife? Other issues may include whether you were married, legally separated or divorced at the time your wife committed the alleged neglect. Why was she responsible for the loss? How was it lost -- foreclosure, I presume, but I don't know.

A tort action of some kind might be a better fit, e.g., negligence, but there is a limitation where the loss is purely economic (as here?) and involves no physical injury. Whether you have suffered compensable harm through your ex's inactions would be determinable only after close examination of the facts and of recent case law.