Yeah, both vertical and horizontal cracking is indicative of something potentially serious being wrong. Pictures at a minimum so we know what level of cracking we're dealing with.
The answer may be, remove and replace the foundation (if possible) or relocate the light on a new foundation if replacement of the existing foundation isn't possible.
Or, if the cracking is essentially shrinkage cracking, you may just be able to caulk the crack and move on with your life.
But until someone can put eyes on it, you can't know.