How do I had emissive light behind walls with hidden shadows?

I haven’t been able to find an answer for this anywhere. I’m making a third person game with walls that are hidden in game and have hidden shadows so the player can’t see into other rooms across the map. The problem is that all emissive materials still show through. I have forward shading turned out because I heard somewhere a while back this was the way to do it, but the problem is still there. Please help me.