Have you ever passed an interesting building while driving through town and been curious about what goes on behind its closed doors? An event Saturday and Sunday is made for the curious to take a peek behind closed doors throughout Minneapolis. The public is free to tour hundreds of private spaces, from historic mansions to factories to performance venues to apartment buildings to places of worship. The event is called “Doors Open Minneapolis.” Kelly Fischer is leading the charge through her organization, Rethos, and she joined MPR News host Cathy Wurzer with a preview.