Necessary conditions for the assembly to work correctly:
1) All normals must be directed outward.
2) You should use Cycles and increase the number of bounces of Glossy rays in the Light Paths tab as much as you need , I use 18.

This geometry nodes assembly creates three layers for any object: Frame , Glass , Lamps. Each of these layers can be flexibly adjusted to achieve the desired result. Each mesh needs different settings as they differ in shape. 

All edges of the original mesh are used to create the Frame and Lamps. If you need that not every edge was used, then you should select the necessary edges in Edit mode , create a Vertex Group and assign selected edges to it, then in the modifier settings, click on the box next to the "vertex group" item and select the desired Vertex Group in the field that appears . This will allow you to create smooth shapes like a spherical object with edges like the cube on the front right side of the demo file.

To add an assembly to your project, you need to click on the "File" button on the upper left corner of Blender, then "Append", then find the "Infinite reflections APPEND FILE.blend" on your PC and click on it, then in the "Node groups" folder select "Infinite reflections". Then select the desired object , add the "geometry nodes" modifier and select "infinite reflections".

Three basic procedural materials are included in the assembly, they are needed to create the effect of Infinite reflections, you can change them or use your own instead, but follow the following recommendations for everything to work correctly:
1) You can do anything in the material of Frame
2) The Lamps material must be Emissive, but with the choice of color you have complete freedom.
3) I strongly do not recommend changing or replacing with your own Glass material, as it is the basis of everything and changing it can ruin everything. Change it if you are confident in your abilities and know what you want to achieve with it.

If scale does not work correctly on your mesh, please use Scale along normals .
Also, if you have problems with Glass shading (or any other layer - Lamps or Frame), try changing the "Glass Shade Smooth"(or another corresponding layer's shade smooth setting) item in the modifier settings.