Lighting problem

I’m having a lighting problem. This scene that I’m making has no light sources inside the box
But somehow it’s very bright.

Any reason why it’s this bright? I’m not good with lighting.

Post-process volume and set the exposure to min: 1, max:1.
Make sure it’s set to unbound to cover the whole area.

You’re using box brushes which are not visible to hardware raytracing and don’t generate mesh distance fields, they are effectively invisible to lumen. Convert them to static meshes.