“A Muslim goes into a Catholic school…” sounds more like the start of a bad joke; but according to a New York Times story, it’s a trend that’s been growing over the last decade. Although there are no official numbers, Catholic schools say Muslim enrollment has shot up in the past 10 years, roughly doubling among men and tripling among women.
One reason some Muslims are picking Catholic schools is they view them as having stricter moral codes and expect student behavior will be more in line with their own values (with many offering things like single-sex dorms). Another reason is that many Muslims feel more at home in an environment where people understand religious behavior and the need to follow strict customs. [Source]