The FvwmAuto module allows you to define actions for when the pointer enters and leaves a window after a specified delay. A common use of this would be to automatically raise windows, which is in fact the module’s default behaviour.
FvwmAuto doesn’t have a module configuration in the same sense as a lot of the other modules. The way this particular module works, is listening for certain events that you can specify. Along with that is the action to be performed (typically a function.)
In its simplest form, the following would raise the focused window 250 milliseconds after receiving and maintaining focus:
Module FvwmAuto 250
You can also use FvwmAuto to do a lot of other things. One power of FvwmAuto is the ability to schedule events when a window (essentially) receives and loses focus . The man page has more examples about that.
 This is not how EnterFocus and LeaveFocus operate, but from an explanation point of view, it suffices.