Ur door bell point should have 5 wires no?
Earth, Live, Neutral, and 2 wires that is from the doorbell switch

the Live should be line voltage so as long as you have that, and earth and neutral u can wire it to become a socket.

But my doorbell point doesn't have the plastic box so even if I wanna convert to a socket I don't have a place to screw the socket onto, unless I drill and use wallplug.

that's not entirely true, actually there's a set of line voltage (220v AC) coming into the door bell unit itself and that is permanently powered. The door bell unit itself has a transformer which steps down to lower voltage that goes to the door bell switch and then back to the solenoid for the actuator

In other words, the door bell unit is always powered all the time, just that the solenoid which controls the door bell actuator (within the doorbell unit itself) doesn't get powered unless u press the switch, so touching the wrong part in the door bell unit will actually get u a shock eventhough the door bell is not pressed.

here's a pic for better illustration, it's from an older post here in LYN as well


here you can see that the AC part is always powered, so what you need to do is just connect the AC power's Live and Neutral, and the earth wire, to ur 13A socket. the wires coming from the doorbell you can ignore them, wrap with black tape or something.

In fact you can even loop the AC power source to a 13A socket and still keep the connection to the doorbell unit (so you get both). IP camera don't think will use a lot of power so it should be fine to loop.

One thing to note, the door bell wiring in DB is usually through a 6A MCB, therefore make sure the electrical appliances that you use on the doorbell 13A socket will not have high inrush current that might trip it.

13A socket normally has 20A MCB behind it, but if you are sure the item you connect won't use much electricity, then it should be ok.