You are wise to be concerned that this is scam. Trustworthy business people rarely make unannounced house calls. However, you should know that Chapter 7 doesn't relieve you of the deed to the house. If you "surrendered" the house in your Chapter 7, your personal liability to pay the mortgage is removed BUT the deed remains in your name until a foreclosure proceeding is completed. You can find out who is the titled owner of the property by checking with the Register/Recorder of Deeds office in the County where the house is located.
My response to this question does not create an attorney-client relationship and does not consitute legal advice. The information is provided as a courtesy only. This format of written question and answer is too informal and lacks sufficient detail. It is almost never possible to give quality legal advice without a full set of facts and the opporutnity to have a dialog where questions are asked and answered. Moveover, posters on the internet should be aware that confidentiality is not guaranteed online. I am licensed to practice law in WI and IN.
When you surrender your house in a Chapter 7, the loan is discharged and with it your responsibility to pay on the mortgage. However, the lien still exists. Until your mortgage holder actually goes through the foreclosure process, the deed will remain in your name and you will continue to be responsible for the insurance and any HOA fees associated with the home. You should check with the recorder's office of the county in which you live to confirm whether the deed remains in your name. If so and if you are benefiting from living in your home, then you can continue to do so until the mortgage company forecloses.
You did not mention if you were current with mortgage payments. If so, you might be utilizing the "stay and pay" arrangement; whereas long as you stay current and continue making payments on time, the lender will not foreclose on the property. If you have not been making payments, then at some point - with proper notice - the lender could decide to foreclose.
You should be weary about selling the deed to your property until you determine whose name the deed is in now and what your goals with the home are. Reach out to the attorney that originally filed the bankruptcy to see if he or she can provide any insight and guidance what you determine these two things.