When shower is running in bathtub, water comes out of light fixture below in kitchen.

Does this only when shower is being used?

Hi Dhartman

What have you done to isolate the leak so far? Have you tried removing the trim plate from around the shower valve and seeing if water is leaking from the valve or the shower arm? Is there an access panel behind the tub drain...if so you should open it and look in while running the shower to see if water shows up upstairs.

Tell us what you have tried and answer Hkstroud's question and then maybe we can help you to isolate things a little better.

Mark