Is 在我们村里有一所中学 incorrect?
Actually, "在我们村里有一所中学" is the equivalent Chinese expression of "There is a middle school in our village."

And the equivalent English expression of "我们村里有一所中学" should be "Our village have a middle school."

"在我们村里有一所中学" often used in written language, if you mean spoken language, "我们村里有一所中学" is more often used than "在我们村里有一所中学".