Birthday Card Mix-Up

My grandparents live in Washington and sent me a birthday card. I received a birthday card from people named “grampa John & Marla”. Not my grandparents. They envelope was taped like crazy, had my name and address, my grandparents address, etc. The theory is that a postal worker opened cards to take out the money, and mixed them up when putting them away. Anyway, the envelope is stamped with a Seattle USPS stamp, so I wanted to see if anyone with a birthday this week is missing a birthday card from their Grampa John & Marla, in case the recipient happens to live in Seattle.

TLDR; mixed up birthday cards, anyone know a Grampa John & Marla? They wish you happy birthday and they love you