You have a point light source behind some walls.
Unity light passing through walls.
Create a unity primitive cube plane etc sized similarly to your wall remove its collider and in the mesh.
These options have obvious edge cases that can t be easily resolved.
This solution works in other engines like unity and ue4.
Although you have enclosed the light indirect light from the light source seems to seep through especially on the ceiling and the floor.
By sydon thursday november 2 2017.
How to fix indirect lights seeping through walls.
You can simulate this in shaders or use raycasts to see if the light is behind a wall.
Shadows are the obvious answer however i assume you are using lite and that s not an option.
Set the point light s baking property to mixed or baked then bake your lighting data using the lighting tab.
This solution works in other engines like unity and ue4.
Light passing through walls 1.
It s really just a shadow type setting that needs to be set right.
In that case you ll need to be a bit more clever.
That s why shadows exist.