Bathroon light and ceiling exhaust fan wiring?
You'll need a pro to sort this out if you're not comfortable rerunning wiring yourself
The problem you have is that the light was run as a switch loop, with an always-hot from the light fixture box down to the switch and a switched-hot from the switch back to the light, but no neutral, as was permitted by the NEC prior to 2011.  However, whoever ran the /2 cable for the fan down to the switch box expected power to be coming in here, or at the very least, for both always-hot and neutral to be available here.  So, you'll need to either reroute the cable for the fan to the light box or replace the /2 for the light switch loop with a /3 yourself, or have a pro do it for you if you aren't comfortable with DIYing that.