After you file

You can't fix it if your return has been efiled, and the IRS has already accepted your return.  (This is my assumption, since this was the topic of the original post in this thread.)

If you entered direct deposit information for a closed or invalid account, the IRS will mail you a refund check.

And, if you entered information for a valid account that doesn't belong to you, there's most likely nothing to worry about. 

However, please see the TurboTax Help article What if I entered the wrong bank account for direct deposit? for actions you can take to secure your refund.

@nestoog68