The wire should be secured so that it is a minimum of 1 3/4" away from the rough-in wood that supports the wall covering (about half the depth of a standard 2x4 stud). This allows you to use standard sheetrock screws and nails and not hit the wiring behind it. If you can't provide that much space you need to use nailing plates or other physical protection.

You could also use metal EMT conduit in or on the wall to protect the wiring. EMT provides adequate physical protection for the wire. If you are only using it for protection from errant nails and screws it is usually treated as a wire chase, so you just need to make sure it has a bushing on each end to protect the NM wire from abrasion.

If you have enough depth to recess a standard receptacle box, you probably have enough depth to keep the wire back from damage. However, it needs to be secured, so maybe long zip ties aound the metal pole would work.

Bruce

Thank you I appreciate it!

Bruce misstates the requirements though his last suggestion is good. It's not the distance from the framing that is important (you can attach it directly to the framing if you want). It's that you can't go through (or along) framing within 1 1/4" (not 1 3/4") without protection of either conduit or a 1/16" metal plate. This is to prevent people who are trying to put nails/screws into the framing from hitting the wire.

Since your boards are only 3/4" (1x lumber is really 3/4). You can't attach directly to the boards, but you an to the post (with listed wireties, for example), as long as you place the wire so that it's not right up against those boards (either as Bruce implies, frame it out from the post a bit or put the wire where it will be at the corners of your box.

Why not just use BX?

BX doesn't provide the necessary protection against nails. It's obviously better than NM, but it doesn't satisfy the code required protection in this case.

BX doesn't really exist anymore either, but Greg is right type AC or MC cable is subject to the same rules here (300.4, etc...) as NM.

Greg - I didn't know it doesn't provide the necessary protection.

Ron - BX does exist, although perhaps not under that name - I bought some recently at a Big Box store.

"BX" hasn't technically existed in years. You're seeing AC most likely. True BX lacks a ground which is problematic in modern wiring (and the armoring can be dangerously non conductive).

"the armoring can be dangerously non conductive"

No kidding! There've been cases where ground fault current heated up the armor to red-hot and started a house fire. A ground through actual BX is worse than no ground at all, IMO.

Confirming the two posters above, see explanation from Electrical Contractor.

OK, Ron I stand corrected.; the cable I bought does have a ground. It's a green insulated wire. I've also seen some with a bare aluminum wire (that was left by the contractors who built my house in 2015.