Those of a certain age will recall "gag boxes," which are little jokes hidden inside a small box. You gave (or just showed) them to people like a greeting card. Irving Fishlove, founder of H. Fishlove and Co. novelties, popularized the little boxes in the 1920s and '30s. Collector's Weekly talks to novelty collectors Mardi and Stan Timm about gag boxes.
Collectors Weekly: What’s with the toilets?
Mardi: Toilets were Irving Fishlove’s thing. Well, anything to do with elimination, really. Fishlove focused on toilets when, in 1924, TootsieToy started making doll-house furniture using a new injection-molding process. One of the items they made was a toilet.
When Fishlove looked at that toilet, he didn’t see doll-house furniture. He saw funny. And so he started making all kinds of gags using this little toilet. The beauty of it was that Fishlove could use the same toilet in any gag box. His strategy was pretty ingenious, actually. He would just order tons of these toilets for gag boxes. All he had to do was change the wording on the box. For example, we have one that looks like a stop sign in a stand, and it says, “Parking Limit 30 Minutes.” And when you open it up, there’s a toilet inside.
Of course, gag boxes weren't limited to toilets -any joke would do, as you'll learn in the interview, along with plenty of pictures to illustrate the concept. Link