According to the postmark it was put in the post box by Sigrid’s friend Elsa in Finspång, in Östergötland, reported local paper Norrköpings Tidningar.
A little research revealed that Sigrid had in fact worked at the home, albeit so long ago that nobody remembered her.
But nobody knows who the sender, Elsa, was. Sigrid’s nephew came forward when the paper Gotlands Allehanda wrote about the card with its picture from the Finspång area. He did not know of his aunt’s friend but said that his uncle left a collection of postcards with images of Finspång when he died.
The two ladies apparently bought lottery tickets together. A lottery number is noted in the postcard and Elsa said she hoped the card would arrive before the day of the draw on the 15th.
It did not, and whether the friends won the lottery is unknown. As is the answer to another question – perhaps for the post office: where has the card been for the last fifty years?