If you really want to contact the people who live at that address, you could check the county real estate tax rolls for that address. In most states, if not all, it shows the name of the owner of the property. (That may or may not be helpful if it is leased.) Once you have the name, you could send a letter with the person's name on it or you may be able to find their telephone number in the online white pages. If you send the letter with their name on the envelope, they may be more likely to open it than if you just send it without a name. Also, if you know their name, they may be more likely to return or deliver the quilt to the rightful owner.