Mattias,
Eric Erickson was part of the Willard Chocolates card set in 1923. I have an image of the card below. He was also part of the Curtis Ireland Candy set from the same year, though I do not have an image of that card.
I have to imagine that his autograph is somewhat difficut to find, but should not be impossible. He lived until 1965, so as long as autograph hunters knew where to find him, and as long as he was receptive to signing through the mail, his autograph should be out there somewhere. Through the mail autograph collecting, even of lesser known players, was fairly well thriving for 20 years or more by the time Mr. Erickson passed away. Don't give up.
There were three other players who were born in Sweeden who reached the major leagues:
Charlie Bold played one game for the St Louis Browns in 1914. He was born in Karlskrona Sweeden.
Charlie Hallstrom played one game in 1885 for the Providence Grays. He was born in Jonkoping Sweeden.
Axel Lindstrom played one game with the Philadelphia A's, then spent the next 14 or so years playing minor league and semi pro ball. He was born in Gustavsberg Sweeden.
Best of luck in your search.
Tom C