I hung a painted sheet of peg board in my room to hang stuff on so I didn't have to put a bunch of holes in the wall. I designed these little peg hangers to hang picture frames and other stuff.
The peg diameter is 0.22 inches, which by trial and error I found to fit the holes on my painted peg board pretty well. You may have to scale it slightly to obtain a snug fit for your application.
In addition to the STL, I included the SolidWorks model in case anyone wants to edit it.