regarding turning on electric light on Yom Tov:
I clearly remember the article in the Jewish Press from over 20 years ago by “Rabbi” Klass permitting them. I read the article carefully and looked up all of his sources. I don’t know what to call that “teshuva” other than an extreme case of Halachic dishonesty.
He claims that the only authority to forbid turning on lights is the Chazon Ish based on boneh, who he maligns as an extreme, compulsive machmir. While the Chazon Ish was certainly an original thinker and his classification of boneh is not accepted by the majority of Poskim, anyone who has ever perused his seforim seriously would know that there are no lack or original kulos to offset his chumros. Additionally it is negligent and dishonest to ignore Reb Moshe who clearly and unequivocally forbade turning on electric lights.
The two sources he quotes as permitting were written close to a hundred years ago and had little understanding of how electricity worked. The Aruch HaShulchan is an unpublished letter written by one of the Gedolei HaPoskim who never saw electricity in his life. The other is from R’ Tzvi Pesach Frank, and fails to mention that he later retracted his psak.
He concludes by misquoting Rav Ovadia Yosef as saying that he wouldn’t do it him self but wouldn’t say anything to someone who did. What he really said is that he would embarrass the person in public, but would certainly tell him privately that he is going against the vast majority of Poskim.
So there may have been ignorant people in previous generations who unknowingly turned on electric lights on Shabbos, but it was NEVER an accepted psak and is by no means a new chumra not to.