Drill getting stuck about two inches into stud

Power lines can be run either through a hole drilled through the stud (i.e. horizontally) or stapled along the edge of the stud (i.e. vertically).

Horizontal runs are generally used to connect multiple sockets in the same room. For normal outlets at about 1' above floor level, the wiring will usually be a few inches above the outlets, but you could have them at other heights too, like if you have a kitchen or bathroom on the other side of the wall, or wall sconces for lighting.

Vertical runs of wire generally bring power into a room from wire runs (that eventually lead back to the service panel) in the attic, crawlspace/basement or the space between floors.

If it's running through the stud, there should be a metal plate attached to the front of the stud to prevent you from driving nails or screws into the power line.

Of course, things aren't always done the way they should be, so you can detect if you have these plates with a strong magnet.

As Legion600 suggested, you probably have steel studs as furring strips. You need to be sure you are not hitting protection plates installed on wood studs.

These protect electrical or plumbing lines close to the stud face, and you must never attempt to drill through these. Usually, if you drill several inches above or below such plates, you will hit wood. If you are hitting metal along the entire stud length, it is not a protection plate, but a metal stud. Metal studs in this application should be fairly light gauge and easy to drill through. Protection plates are about 16 GA and are not easy to drill through.

You may anchor objects to metal studs. They are sturdy enough when finish sheathing is attached along their length. Do not use toggles, the hole required is too large. It's best to use a number of self-drilling screws that are barely long enough to engage the stud face material after passing through the mount and wall finish. This avoids damaging any lines routed through the center holes of the stud. You can also use self tapping screws into pre-drilled holes, but drill very carefully so as not to damage any underlying lines when the drill breaks through the face material, and again, use appropriate length screws.