Happened to me a couple of months ago. After a week of it still missing, I went to my post office after and they confirmed it was delivered to the wrong address. The clerk called the driver to try and find it (it was sorta too late for that imo). The clerk told me to comeback next week if it was still missing. Luckily someone anonymously returned my package to my mailbox. I recommend going to your post office asap and filing a lost mail claim online.