Check out this excellent explanation from Great American Insurance Group of the history of known faulty electrical panels that are fire risks.
“In your electrical panel box, look for any panel labels that say:
Zinsco
Sylvania
Sylvania-Zinsco
GTE-Sylvania
Manufacturers or vendors of Zinsco-style circuit breakers include:
Challenger, Challenger Electric
Connecticut Electric, also known as Unique Breakers, Inc. or UBI
GTE Electric
Kearney Electric
Millbank Electric
Thomas & Betts Electric”