Yup. So many times. The school district sends home notifications if our student(s) have been exposed to a positive case in class.
One kid is in middle school. And with students moving between six classes a day, we practically got a notification every day for two weeks.
Our school district also sent home two tests for each kid right before winter break. With instructions to take on specific days. That alone kept more than 200 positive cases off campus.
We also used some at home before sending them back to school after our isolation period ended. It wasn’t required if you completed the full ten days. But I wanted to be sure.