Have you ever looked at 1950s electrical wiring? How about electrical appliances from the 1950s?
We used to have Christmas tree lights from the 1950s that were passed down from our grandparents. Two unshielded wires and no fuses, we burned out many an outlet and tripped the breaker every year.
The original claim was house fires in the 1980s of electrical origin. That stock would generally have been built since the 1950s (largely 1960--1990, for the decade of the 1980s).
Candes, fireplaces, cigarettes, and cooking stand out in my memory.
A current industry report puts cooking as the greatest risk, followed by heating equipment. Electrical ranks third:
The basic mechanism to reduce such risks was established in the '80s.
The 1880s: https://en.wikipedia.org/wiki/UL_(safety_organization)