My husband bought a house paid cash for it back in 2008. It is in his name alone. His dad is trying to get him to put it in his name in case we divorce so I want get it or if he passes it goes to his family. We have been together since 1998. What can I do to stop it

This is not a marriage relationship issue it's a Family Law issue so its been moved to the appropriate forum.

What you do is consult an attorney. Whether what your father-in-law is suggesting is legal or not will depend on where you live (a key factor you left out). Many states have laws that state that assets acquired during a marriage are marital assets and can't be disposed of without both spouses agreement.

A local family law attorney can explain where you stand and how to protect yourself.

Well it is obvious someone appears to be planning a divorce, so file for divorce now before the transfer was made, if your attorney believes you have a claim to part of it.

Was the house bought after you were married, and/or do you live in a community property state or country.

Some follow ups
1 where did the money to pay for this hosue come from
2. is the relationship so bad that divorce is being considered already
3. why would your husband not want you to have the home you are both living in