Metal Buildings and wiring

I want to install a flood light on my metal building, but I do not know the best way to do it. Do you install the octagon box inside the building and cut a hole in the metal or install a weatherproof box outside? If I put a switch inside, what kind of box do I install that would attach to the metal stud? What type of screws should be used?

Thanks,

Joe

Either way on the box will work.
As far as a switch box, they make all kinds of metal ones to mount on metal studs. It's done in a commercial installation every day. The box stores sell them

I didn't realize some of the outlet boxes were dual purpose wood and steel. After your response I took a closer look and noticed the holes in the side for use on metal studs.

Thanks for the help.

Joe