will now mail you a PIN number that you will have to put in the return or the IRS won't accept it.
By the way, you probably won't be able to electronically file your tax return this year because the IRS database already has a return for your wife's social security number. Just paper file and then you will get a letter asking you to confirm who you are. You should also file this form:
https://www.irs.gov/pub/irs-pdf/f14039.pdf
I know it stresses people out, but it happens often. It will get corrected.