Recently Google update its Search app for Android 5.0 Lollipop version devices which will allow you to ON/OFF your Wifi, Bluetooth and Camera LED’s flashlight with your voice. The thing you need to do is just update Google Search App on your Android 5.0 Lollipop version, then you can use these commands.
To use these commands just tap on search button in the search bar, or just say “OK, Google” command, if you have that set up. Next, simply ask the service to ON/OFF your Wifi, Bluetooth or flashlight.
For example: “OK, Google, turn on Bluetooth/Wifi/Flashlight”
A Google Now card appears and shows you what’s being toggled. You can touch the card to adjust the toggle if you asked for the wrong one or changed your mind. Additionally, if you have the volume on, you’ll hear confirmation of the action being spoken to you. I’ve tried some more commands, but none seem to work beyond these three. Airplane mode, Location, Brightness, and Volume still send you to their settings tabs. NFC and Data aren’t even recognized as triggers.
Source ==> AndroidPolice