Comment of rtr12's post. Commercial installations, it is very common to have 480/277 volt and 208/120 volt circuits mixed in the same conduits/boxes. You can not depend on color codes for identification. Something beyond the hair on the back side of your fingers is a huge safety factor. Those voltages, I listed above, are a "no fun" experience.
When in business, I would get one or two wild/weird experiences per year of this type of insanity. Hopefully all went home that evening. There was, and still is, a reason for safety meetings on a regular basis.
