Can a mentally ill person will his property to wife?

In general, a person must have testamentary capacity in order to make a valid will. Testamentary capacity requires the person to understand the nature and effect of making a will, to understand the nature and extent of their property, and to be able to make rational decisions about how to distribute their property.

If a mentally ill person is found to lack testamentary capacity, then any will they make may be considered to be invalid. This determination is typically made by a court, which may appoint a guardian or conservator to manage the person's affairs and make decisions on their behalf.

However, there are some jurisdictions that have adopted "substituted judgment" laws, which allow a court to uphold a will made by a mentally ill person if it can be shown that the person would have made the same will if they had been competent.

Therefore, the answer to the question of whether a mentally ill person can will their property to their wife depends on the jurisdiction in which the will is being made and the specific facts of the case. It is always advisable to consult with an experienced estate planning attorney to determine the best course of action in these situations.