In fact, no one has conducted any long-term studies on how the radiation of a wireless network affects a person for 10-15 years of life in the network coverage area. Of course, network equipment manufacturers say it's safe. It is also unlikely that a mere mortal will be able to check whether this is true or false.
On this topic, I really liked how it is described here https://nastroisam.ru/nado-otklyuchat-wifi-router-na-noch /
In general, if you have the opportunity to turn off the router, if you do not need it, turn it off. Why would it work for nothing.
In short, when I was in my first year, I had a neighbor from the 2nd year (a physicist too). Our router was on the nightstand, next to his bed. He turned it off for the night, arguing that cheto, s @ ka, affects his brain and something exponentially fades. It's not at all strange, he spent all day filing anime (yaoi God forbid) and listening to Japanese music, well, with voices like multicolored ponies. Then he generally moved in next door to the command. Strange guy. I somehow made a foil hat for him and wanted to give him, because I liked to surf the Internet at night, but he said that I was a moron and went to bed (turning off the router). Well, I put a hat on it anyway and turned on the router.