Your wife reads other peoples mail?
I've divorced wimmin like that for less.
Anyway what's to be suspicious of ~ she knows me, we have spoken, she knew I was on holiday because I told her I was going when we spoke whilst you were in hospital. What more natural than I should send you a postcard?
Anyway it was only a picture of a donkey and I wrote something like "We are saving a place for you in the Donkey Sanctuary should you feel the need ~ You can be called Mr Norks" ~ innocuous enough to someone who has been in hospital I should have thought, designed to cheer up the invalid and all that.
BTW The Donkey Sanctuary is real (I got the postcard there) and welcomes helpers during the holiday season. I used to work with a guy whose wife went there every summer for a month. Unpaid but all she could eat etc. She too was mad about Donkeys.