As above look at pictures Mr Norman is correct it needs another cable going back to the router and WiFi is probably just your phone or device viewing via WiFi
But then I suppose if box is big enough you could also house a powerline adaptor with PSU and send back data through that , it might work might not ......
You could put a box PSU where cable enters the wall inside depending on if it looks any good , so 240 in and 12v to camera or whatever it needs then WiFi to router or whatever