Every year we get a card addressed to someone else, but with our address. By a process of deduction we worked out years ago that it was actually addressed to the person who lives at number 2 (we live at number one).
Every year for more than ten years, the card arrives and we go and deliver it to the rightful owner (an elderly lady who lives opposite and up the road a bit).
This year it didn't arrive. 
Part of me wonders why and hopes that nothing untoward has happened to the sender.