Gene Roddenberry's first sci-fi show pitch from 1955: "The Transporter"
I thought this was an interesting read. You can see that the seeds of what would become Star Trek were already growing.
Also, despite the name "Transporter" sounding familiar, his description of it is closer to a holodeck. It "transports" the user to different scenarios. Wild.
The ending bits that imply a darker vision of this future suggests a very different direction for the show. Still, there are Star Trek episodes that do consider the holodeck from this angle. Maybe we need a mirror universe holodeck episode.
The second paragraph reads a lot like what would end up becoming the Talosians in the cage, although the device sounds like the neural interface they had on the Equinox, in place of the Holodeck.