I thought this comes off by default, anyway, just go to Settings-Device-Accesibility-Dexterity and interaction and turn it off there.
BUT it has happened to me once, so Force Stopping it and then turn it on again (Going to that menu and turn it off and on again) it fixes the battery drain, Until next time...
I think a reboot will do just the same, try and see.
Ah, thanks SO SO much for this! I turned this feature on with Nova Launcher (not realising the option was in the settings) and then used Nova to turn it off and even to force stop the process, but then I kept noticing my phone screen turn on when my hand went near it.
Low and behold, the setting was still on in the above mentioned menu. I've now switched it off, hopefully for good.
FYI, for anyone reading this topic in future, my setting was in Settings>Personalisation>Accessibility>Dexterity and Interaction
I wonder if this'll help my battery out much. Air Wake Up wasn't even shown in my battery usage. (Weirdly, Bluetooth wasn't either, and these days it's on all day for my Android Wear and my car.)