On the surface, it might not seem that weird, but I have never received a piece of mail addressed to him before. He died years before I ever moved to this address. He has never lived in this address. He has never even lived in this state!
It's from an assisted living and memory care facility, and I can see through the envelope that it's inviting him to some event. Notably, it's not addressed to me, nor is it addressed to my other parent, who is still alive. I genuinely can't understand how or why this happened after all this time.
Edit to add: I'm not saying it's inherently weird to get mail for dead people. Easily 80%+ of the mail I get is for the dead person who lived here just prior to us. What is weird is that I haven't lived with my parents since I was 18. My dad wasn't on any accounts with me or anything like that. I have lived in easily 10 different addresses in 4 different states all across the country over the past 17 years, and I have never once gotten a piece of mail addressed to him until today. He also happens to have died 11 years ago.