I liked the “Don't Panic” sign by muzz64, but it didn't really give me Hitchhiker's Guide vibes, so using the blank sign as a base in Fusion360, I rewrote the text using Gill Sans Bold Condensed and adding an exclamation mark.
I'm still working out how Fusion360 works, so the scale is horrendous. Print it at 10% scale for a nice size, or as big as y'like to create a slip/trip hazard. :D
The sign in the photo was printed in Aurora Fiberlogy Easy PLA and ERYONE white.
The author remixed this model.