I helped my grandpa install a light fixture in his kitchen(he's in the process of remodeling) and noticed the wiring was a little weird. The wiring is going from the fixture to the switch which I thought, and a google search confirmed, is supposed to go like this:
However, this is how the existing fixture was wired and how my grandpa insists I wire the new fixture:
The wiring diagram at the top of this page belongs to do-it-yourself-help.com. The original can be found here: https://www.do-it-yourself-help.com/wiring_switches.html
I'm not good with diagrams, but whats happening is the hot is coming from the breaker box(the neutral too, but it's ignored) going into the fan, and then out of the fan to the switch. The switch is then sent to neutral on the breaker box.
He's going to be due for an inspection once all the wiring is done and I'm concerned about this. The guy who did his wiring said he did all rooms like this. This area is under NEC 2005