I'm near Pittsburgh. House built around 1953. We have had tornados lately. I also have basement. I can see where the walls have bent the
10 inch joists down over the years. Another trouble house was built with a main bean of 4 8X2 s. I reinforced that. I'm still leveling.Greg
*That is a heavy duty wall. I suggest a RotoZip tool with maybe a cement board bit or possibly a diamond bit. For a quick square cut, not-too-accurate of a hole, an angle grinder with a diamond blade will be fast, but dusty. I have a little Makita cordless saw. I can put a 3" diamond blade on it for cuts such as yours. The 9.6 volt battery doesn't last too long though.The hole saws that RBM suggested are perfect for recessed lights. They are available in several sizes to accommodate different manufacturers. You can also get tungsten carbide hole saws the same size as round electrical boxes. Check McMaster.com