See last question Q. Thank you for your fast answer. I have other doubts regarding the above since I see that many very religious people don’t seem to care much about the above danger. Also why is the Mezuza not a protection?

Kaf Hachaim (239) mentions that the above applies even when there is a proper Mezuza. However, Eishel Avrohom is then lenient. Horav Aharon Miller Shlit’a mentioned that the reason why few people seem to care these days about the above danger, is that many Poskim maintain that the above only matters when sleeping a house that is totally dark and not in a place that is lighted even by the moon or even by another slim light. Recently we mentioned that change in lighting by a Shaila regarding Shabbos candles lighting in bedrooms. It is most common in our days that total darkness is non-existent, as the light from the street. corridors, electric clocks, phones, night lights, adjacent rooms etc., avoids it and therefore the danger mentioned does not apply. (See Eishel Avrohom 239, Daas Torah ibid., Dovev Meishorim ibid., and others) In addition, some are of the opinion that the danger pertains only to lone houses in the fields. (See Betzel Hachocmah 4: 76)