I created this housing according to following demands:

• not fix mounted to the printer, but "somehow" connected
• holding 2 step-down-converters, one 24V to 5V for the Raspberry Pi 3B and one 24V to 12V for the hot end lightning
• no fixed cables and no soldering

1) To make it more or less stable but easy to remove i created a slide-2-fix holding, which connects the housing to the holder, which itself is kept in place by the back right printer foot which has the anti-shake feet attached (https://www.thingiverse.com/thing:6649634).

2) Connect a cable in the bottom case at the PSU, lead it out of the printer and plug it into the connector in the housing.

3) To make it easy to remove the cables i place 2 JST-2-Pin connectors (https://www.amazon.de/gp/product/B06XRBKSY2) which must be secured with M3x4 grub screws as otherwise they could be pulled out when trying to disconnect.
The second connector delivers 12V for the hot-end lightning i use (https://www.thingiverse.com/thing:6368214) and the cable has to be fixed with the RibbonCableClip (5 or 6 pieces) to the hot-end-cable and leads below the printers back to the box.

I prefer screw terminals instead of soldering the different cables together, as i wanted to make it easy to change if e.g. one step-down-converter dies.

The camera with the holder and housing (https://www.thingiverse.com/thing:6695360) can be connected to the Pi and the "spare" cable can be pushed into the housing as the cable is stiff enough that you don't need a guide or holder or so.

You'll need 10 to 12 M3x6 countersunk head screw to fix the converters and the Pi (with 2 or 4 screws) and the lid to the case.

All the connecting cables are soldered to a JST-plug (male or female) and wrapped in insulating fabric tape, which normally are used in cars (https://www.amazon.de/gp/product/B0029XY3UE)

The last thing is to connect the printer with an USB-cable to the Pi and your Enders can be controlled via Octoprint.