NM was popular then too <1955>, the fabric covered type with the undersized ground wire.
That was the way our 1954 house was wired. My understanding was if you had a government backed loan like "GI" it was required to have a grounding path in the wiring method at that time. That is what my dad said anyway. One of my first electrical experiences was retrofitting receptacles to 3 prong with my dad and granddad (an electrician)
I know in 1971 when I bought my first house of my own they told me it wouldn't pass the GI bill inspection but they wouldn't say why. Now I assume it was the aluminum wire.
It didn't bother me since I did have the down payment and they matched the GI interest rate.
The whole "GI inspection" thing may just be for folks in the DC area since others in flyover country have never heard of it.
BTW my ex still lives there and has never had a problem with the wire.
