The question of changing electricity, what are these lines, how to take them, and which one is the main line of entering the house?

The 8-core wire in figure 1 is a network cable, and now blue-red multi-strand copper wires are rarely used (generally, single-strand copper wires are used for 220V power lines in walls, and multi-strand copper wires are also used for weak current).

Figure 2. The two 8 cores of the information box may be one in and one out, one out may be to your master bedroom, and the other is to the external network. You can use an electric meter to measure (if you don't have tools, you can use batteries and small bulbs to measure)

Figure 3: The general 4-core wire is the wiring of infrared anti-theft probe (I wonder if you have it at home? ) It may also be the wiring of the visual doorbell.

The above is only based on pictures and is for reference only.

It is suggested to confirm with the property company that the wiring of each building is generally clear only to the developer and the property management.