You would think that after all this time a home could be treated somewhat like a car sale. Not yet buddy. In reality on loans for homestead properties (whether it has been homesteaded or not) a lender is going to ask the spouse to sign the note, despite that spouse not being on the mortgage. Why, because it makes the spouse as well liable for repayment of the note. I'm not sure if you know this or not, but anyone's signature that appears anywhere on the face of a note is liable for repayment, therefore why notes aren't notarized. I hope this was somewhat helpful.
Might I suggest that in the future, your wife be the one to purchase cars and other misc credit items and you be the one to get the mortgages. This helps keep your debt to income ratio low so that loan approvals run smoother.