Ball from another court

[Scrapper1]

I mentioned in a previous thread that I was working solo today. I was working my JV match directly next to the court where the Varsity match was taking place at the same time.

While the ball was being played far from the net on the receivers' side of my court, a ball from the Varsity match apparently rolled onto the servers' side. It was cleared quickly enough by a serving player that I never saw the ball on the court. After the rally (which the serving team won), a player told me that the ball had been on the court.

1) Once I have this information, is there anything I should do about it?

2) If I had seen the "varsity" ball while the "JV" ball was still far from the net, should I stop the rally? (Even though it doesn't seem to be interfering with play.)