My wifi turns on randomly and automatically.
KitKat has a feature where, when Wi-Fi is turned off, it periodically scans for networks to allow Wi-Fi-based location detection to work. To turn this off:-


Go to the Wi-Fi settings
On the overflow menu (the three dots) select Advanced
Uncheck Scanning always available


Even when an app turns on Wi-Fi fully, this isn't done with an intent; rather, it's done by calling the method WifiManager.setWifiEnabled. Only apps with the permission  "connect and disconnect from Wi-Fi" can do this.