It might have just been a mistake on someone else's retun. They might have typed their dependents ssn wrong and got yours by accident. Double check your ssn, maybe you typed yours wrong.
You will have to print and mail your return. Then the IRS will mail you both letters to straighten it out.
How to mail a return from the Online version
https://ttlc.intuit.com/community/printing/help/how-do-i-print-and-mail-my-return-in-turbotax-online...
Be sure to attach copies of your W2s and any 1099s that have withholding on them. You have to mail federal and state in separate envelopes because they go to different places. Get a tracking number from the post office when you mail them for proof of filing.
