This is a remix of a design i found here:
https://community.symcon.de/t/7-touchdisplay-wandeinbauloesung-unter-100/45295/18
The original assumes you can screw your case to the wall on the sides, mine adds holes at the back and some more ventilation holes.

This is to mount your original raspberry pi 7" display (+pi) in a (massive) wall.
Need to make a hole, 4 cm depth.

Also Required:

• 4x8mm cylindric magnets, 8x. Found here:
  https://www.amazon.de/corpus-delicti-Magnet-Design-Power-Magnete-ultrastark/dp/B007WSNUE6
• screws and wall plugs, the holes at the back are 4mm diameter
• original raspberry pi display 7", DSI cable

Creality

Ender 3

No

No

200

15

Printed everything with layer height 0.2, for the case 0.4 might be sufficient.

You'll need the "Gehäuse" once and four of all the other parts (screws, magnet holder for case, magnet holder for screw)

The magnets are put into the holders with a gripper and some force, they will sit really tight.
Be aware that magnets have poles and insert them with opposite poles so they attract their counterpart (i managed to mess this up more than once)

Printed screws are put into the backside holes of the display.
Glue the holders to the case / screws after magnets are in. Preferrably long holders to the case, short holders to the display.

See original forum thread for further information / pictures.