You're going to have to do more research on this one yourself.
Were you married at the time? Did anyone have access to your social security number? Did you sign a power of attorney (POA) or other document authorizing another party to file on your behalf?
Also, if the IRS believes you should have filed a return based on tax reporting statements, and other documentation or evidence, they can file a return on your behalf.
No one here can really track this down for you, unfortunately.
