Hi, Based on our feed back I have started to convert all the lights over and add in some new ones. It's the new ones I'm having the issue with. I have a covered bridge - with windows. Opposite these windows is the cliff (dispacement) face which runs along the length og the bridge. Inside the bridge there are rafters from where the ligths hang down. If you look the the bridge along the cliff from the outside the light is seeping (leaking) out below the floor of the bridge where it needs to be dark. I tried putting a brush on the inside of the floor - with the block light texture but it's still leaking. I have tried to even extend the block brush out into the displacement to the nodraw wall to stop it. Any reason why it leaks and do you have any suugestions on how to fix it?