Wifi Fixer 0.8.x has a list of public intents which it honors.

As a user, this allows you to use several apps on the market to control Wifi Fixer, telling it to turn wifi off or on, toggle wifi, enable or disable the service. You may, for example, wish to have Wifi Fixer disable the service when you go to sleep, and also disable wifi to conserve power, then restore both when you wake up.

As a programmer, it lets you gain exclusive use of WifiManager, if you need it, by disabling the service.