Speaking for myself, I usual just command strip the thing I want to hang to the wall. After all, whatever you print to attach to the dry erase board will likely need to be attached to the board. Why not just attach straight to the wall? You could also potentially print something that mechanically attaches to the dry erase board and attached to the wall via command strip.
You probably want to look for "command strip" and will have to dig through the results. Here's thingiverse: https://www.thingiverse.com/tag:3m_command_strips It looks like most of the results are what I described: "here's a mount for this specific thing that attaches to a wall via command strip", but if what you're describing exists it will be in those results.