Strange lighting artifact on modular walls

Hello, I’ve been working on creating modular pieces with interior and exterior wall faces. I’ve spent a lot of time getting the UV’s to line up for material tiling but am now facing an issue with the lighting within the engine creating weird artifacts when I move a light, also happening with movable lights. Ideas?

More information; Walls are boxes. Happening on both sides.

Ok, I’ve worked out that it’s caused by the light itself. The issue has been resolved by changing Shadow Bias from 0.5 to 5 within the light setting. Probably caused initially because my 0 channel UV’s are really huge (method I’ve used in 3DS Max to get uniform scale between different modular pieces is to UVW Map them with real world scale.).