Having worked in family law... the house more than likely is separate property when it comes time to divide up the marital assets. The value of any improvements that have been made would become community property. But for purposes of having him removed because her name's on the deed, that probably won't fly because he HAS been living there and they ARE married. It would take a court order to get him out. Additionally, in a case like this a Judge would look to a prenupt first (if there is one) if not, then they would go from there.

Widowed 11/10/12 after 35 years of marriage
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“In a sense now, I am homeless. For the home, the place of refuge, solitude, love-where my husband lived-no longer exists.” Joyce Carolyn Oates, A Widow's Story