Dafdigest for Eruvin 105. I have extracted parts of the article which speaks about workers working in the Temple on
the plating which was fastened on the walls of the Kodesh Kodoshim.
The inside walls of this special chamber were plated with gold panels,
which were attached to the walls by artisans and workmen (see Mishnah
Middos, 4:1,5). If we do not
have a qualified kohen to do the job, we can use a Levi, or even
a Yisroel. Instead of walking in via the route taken by the Kohen
Gadol who entered on Yom Kippur, these workers were lowered into the
Kodesh Kodoshim from the roof, enclosed in a special box which had a
small window in the side. When the box was lowered to the appropriate
position, the worker would open it and reach out to do his work.
The mitzvah is that they enter in this suspended box, but, if
necessary, the worker may even enter through the doorway (see Tosefta,
Keilim 1:11). It is noteworthy that Rashi mentions that the gold
plates described in the Gemara were to be used for lining the walls of
the Kodesh Kodoshim. Yet, the words of the Baraisa brought by Rav
Kahana speak about these workers coming to the area —between the
antechamber and the altar. These workers were allowed in the holy
areas to bang and work the gold. In other words, not only did they
enter when it was necessary to fasten these plates, but they even came
in to work on them in the first place. We see, surprisingly, that
although this work could have been done outside, yet, the workers were
allowed to enter the Mikdash and work inside, even in the area between
the altar and the Ulam.