When the generator broke in my son’s Yeshiva, HaRav Shteinman ruled that bathroom and stairwell lights are Pikuach Nefesh.
He allowed a Yid to turn them on? And if so, would he also allow it in a private home? Or (much more likely) perhaps a dormitory setting is different, so if the Debriciner was mattir in the home, there would have to be a different reason. I haven’t seen the teshuva, but if he was mattir, it may have been in a situation where there were small children, who have a din of choleh, so amira l’akum would be permitted.