What the hell? I thought they wouldn't spawn in your house if it was well lit. I'm two years into my world now and so far I have only occasionally emerged from my cellar to find one had spawned during the storm on the main floor, and the last several storms that didn't even happen when I started spamming more torches during the storm. Now I just went to sleep and woke up in the middle of a storm ( normally I wake up right when the storm starts so I can run down to the cellar ) with a deep bowtorn in my house, and the second I killed that, 3 drifters jumped me. They were also all flickering and glitchy looking, like they were phasing through the walls or something.