This is an alien lamp that can be mounted on a wall. The spacing between the mounting holes on the back is 90 mm.
The front and back parts fit together with a friction fit, staying securely in place while still being easy to separate if needed.
 

I used this very inexpensive LED light strip: https://s.click.aliexpress.com/e/_c3DySCUD (3-key switch, natural white, 0.5 m) also available on amazon https://amzn.to/4nlVafY.  It connects to a USB charger or computer port and only draws up to 500 mA at maximum brightness, so it’s safe to use with most USB ports. It also has three buttons that allow you to turn it on or off and adjust the brightness. It looks much better with the light in real life than I can capture with my camera. This LED strip already comes with sticky tape, just glue it to the inside of the bottom cover.
 

If you purchase through the link above, I receive a small commission, even if you decide to buy something else. I’d really appreciate it if you use the link to support me. The price remains the same for you, aliexpress simply shares a small portion of their earnings with me. Thanks 😉
 

Pro tip: if you want a subtle glow on the wall, you can print a few layers with white filament on both the front part and back part side walls to let the light from the LED strip pass through.