On Monday, September 28, 2015 at 12:11:53 PM UTC-4, wrote:
On Mon, 28 Sep 2015 05:35:53 -0700 (PDT), DerbyDad03
wrote:

I spent the weekend helping my Dad prepare his house to be put on the market.

One of the tasks was to remove the light fixtures from a bathroom. After
removing the fixtures themselves, I was left with the mounting plates shown
in the following picture.

http://i440.photobucket.com/albums/q...pssjkqsr1x.jpg

When I removed the plates I found that the electrical boxes were not attached
to the studs, instead they were attached directly to the back of mounting
plates using a threaded tube and strap, similar to this setup:

http://i111.photobucket.com/albums/n...j/DSC03039.jpg

The threaded tube came through a hole in the center of the mounting plate
and was secured with a nut. The mounting plates themselves were screwed
through the wallboard into a stud. Obviously, when I removed the plates, the
electrical boxes came out with them.

Is this an acceptable method of installation?

I am not sure how he got through the rough but if it was "securely
fastened" on the final it is legal.

If the hole in the wall is the regular size, use an old work box and
get on with your project.

It looks a lot like the bathroom before we remodeled,
Pink tile and all.
http://gfretwell.com/ftp/new%20room/New%20bathroom.jpg

There may never have been a rough or a final. This house was built by my
grandfather in a small Massachusetts town. Grandpa was a mason who laid
many of the millions (?) of bricks for the paper mills along the Connecticut
River in Holyoke, MA. I'm sure you know how things were done back then.
There may have been permits, there may not have been, but I'm pretty sure
there weren't any real, formal inspections.

[When my Mom was in grade school Grandpa started building a new house for
his family. (not the one we're discussing here) He ran out of money after
building the basement, so he sold the house they were living in and
they moved into the basement of the new place. Over the next year or so,
he and other family members built the rest of the house above them. I'm
pretty sure that wasn't "allowed', even back then, but many things were
ignored, depending on who you knew. (Just like today, I guess)]

Aside from that, the fixtures are not even close to original, so even if
whatever was there before was inspected and passed, this installation was
done some time long after the house was built.

Thanks for the answer. It we reuse the fixtures, I'll put it back together the same way.