Generally speaking, a mortgage is effective if the person who owns the real property signs a mortgage which is then recorded against the real property. Sometimes, you would not sign the mortgage because another, authorized person is able to do so pursuant to a power of attorney, for instance. Or, a mortgage will be enforced, legally or equitably, if you received the proceeds or the benefit of the proceeds, as mentioned by my colleague. Bear in mind, a notary swore that they verified that you personally signed the mortgage physically before them, so "forged instrument" claims can be very tough to succeed on. If you still believe that the signature is not yours, speak to an attorney and bring all of the documents.