Are there expected dressing norms at faculty interviews? Will a casual tee-jeans be discouraged?
In the same vein, what is expected when a student visits the campus for an interview?
At the SLAC where I used to teach, there was a circulating story of a job candidate who showed up in a t-shirt and jeans. They were summarily shown the door.
This is even though it was a pretty casual place -- I wore a t-shirt and jeans most days during the warmer months.
Dressing nice without looking like you are going to a funeral, the prom, or a beach party is the tricky thing -- especially for women. Men can wear a dress shirt, necktie, and casual sports coat. Women have fewer dressy options so we tend to default to pantsuits.
Dressing more formally than is the norm means that you misread the university climate or that you might have been nervous and overcompensated.
Dressing less formally than is the norm means that you misread the university climate or that you might not being thinking seriously about the position.
Given the dangers of the latter, it's clear that dressing too formal is safer than dressing too informal.