According to Wikipedia this type of sign dates back as far as 1955 at IBM, and a copy was reported at London University's Atlas computer facility. These signs were usually posted above office machines mostly in computer centers, as a warning not to touch, or mess with the machine. The sign is also reported to have been seen posted at the Cavendish Laboratory in the 1950s on an Electron Microscope.
It uses White, Black, and Red colored PLA filament's, and was created and Powered by Make My Sign from MakerWorld(makerworld.com/makerlab/MakeMySign)