I have a lamp and a camera lamp installed outdoors, which are single-on and double-controlled. Can this line be connected to the camera for a long time? How?

Directly connected lights usually have only one wire.

Generally, a camera has two wires, and then the 220V alternating current is converted into 12V-24V electricity through special transformer equipment.

Therefore, it is generally impossible to connect electricity from the light switch.

You need the lamp power supply circuit at the next higher level, such as open circuit, leakage protection and so on, to get electricity.