I have noticed some water streaks on the wall below one of my skylights in the ensuite.
Also, there is a bit of a bulge in the drywall on this same wall. I'm not sure if it is the skylight or my cedar shake roof. How do I determine where this leak is from and how do I repair it?

Remove the drywall where the bulge is and see what is going on up there, or hire a roofer to look at it.