There is some electrical running up that way if I am remembering right from our bath vent fan install.
Good call on changing the torture rungs to ones that actually work. We've considered using standing on those rungs as a sort of timeout for unruly behavior for our children. Then we decided that might be considered child abuse. 😮
This is another - if you figure it out, post pics. Maybe I need to go find a 4200 to look at. Ha.