These are guesses but I think the main reduction in fires from 1950 to 2022 are:
a) better electrical wiring and circuit provisioning. Overloaded outlets or circuits were more common in the 1950s. Fuses could also be tampered with more easily than circuit breakers.
b) Matches everywhere. You had matches in the kitchen for lighting the stove, and around the house for lighting cigarettes. "Kids playing with matches" was a common cause of fires. You don't hear about that nearly as much today.
Arguably came and left. In the early 00s battery pack explosions in cell phones wasn't a super rare event. Now Li batteries are a lot safer with better protections to keep fires from starting. Additionally, the biggest batteries someone is likely to setup for their homes are LFPs which are quiet resistant to starting fires. If sodium batteries are successful they'd go even further in being a non-issue.
I think that many rural homes were still in the process of getting electricity around 1950 and that there were some that still used kerosene lamps for lighting.
a) better electrical wiring and circuit provisioning. Overloaded outlets or circuits were more common in the 1950s. Fuses could also be tampered with more easily than circuit breakers.
b) Matches everywhere. You had matches in the kitchen for lighting the stove, and around the house for lighting cigarettes. "Kids playing with matches" was a common cause of fires. You don't hear about that nearly as much today.