Strange light on walls

what the hell is this ??

We are going to need some info. What lights do you have in level?

I am not using any light :frowning:

So you have no light source at all? No point light, directional, skylight, nothing but you have some reflectance on the mesh… Wow. For the hell of it goto build setting and rebuild light. If you ever had a light in scene and deleted it without rebuilding light that could be the problem.