This person came to our door saying he was with ADT. I confirmed that he is not with ADT and that they do not send employees out to disconnect panels. He wanted to come into our home. We sent him away and he did not return.
He is driving a red Mercedes. Beware!
https://VIDEO_URL?video_id=5e45ee6d74b94ca8b764661b5a01e4ddSsS
I would report him to police. ADT will not come to your house to disconnect a alarm system even for new owners. They will just not monitor the system if no one is paying the monthly fee and unless the previous owners gave you the codes the system is useless to you. They might send someone to try to sell you a monitoring service (usually by mail though) but will never ask to come into your house.