Obviously, it doesn't mean "come in" in the sense of the red light over a street door.

当然，它不像临街灯一样表示,进来吧。

耶鲁公开课 - 文学理论导论课程节选

All right. Just some other examples: a red light over a street door.

好吧，现在让我们看看例子：,临街门上的红灯。

耶鲁公开课 - 文学理论导论课程节选