I haven’t been able to find out much about this little piece. Says “nibroc Kraft towels manufactured by brown company Portland, Maine USA” (Measures 3.5”). All I could find was that it could be from the 30s, and maybe was fixed onto the paper towel dispensers in bathrooms?
I would think you're correct about the usage of the sign, but it looks a bit 'industrial' and so perhaps from a dispenser in a workplace?
From “The Brown Company: From North Country Sawmill to Worldʼs Leading Paper Producer” – a presentation by John Rule.
In 1921 the first wet strength towel was developed by W.E. Corbin. These brown Nibroc (Corbin spelled backwards) towels were folded to fit into wall-mounted metal cabinets and became one of the most recognizable paper products in the country.
For years the machines producing these towels were proudly named “Mr” or “Miss Nibroc.”