The SSN is entered by the user, not TurboTax. You can go back to My Info and make that correction and try to e-file it again. You might need to click on Add a State to get back in to the return--you do not really have to add a state, but that will allow you back in the return. If you are getting a refund there is no penalty for filing late.
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**