This question, already 48 in a row, was asked by the reader Anastasia. And I continue to publish for the "question-answer" section. Let me remind you that if you have your own answer to a question, then write it in the comments below. I and other readers will be happy to read it.
I quote the text of the question verbatim:
Hello! The apartment has already been renovated, all wiring is within the walls. Only switches and sockets are removed. Outlets are categorically few. Can cables be pulled outside? And where to get them from?
I considered the issue and consulted Anastasia within the framework of my knowledge and qualifications as follows:
As a rule, all switches break only one phase conductor for switching electrical equipment. And to connect a plug socket, you need both a phase conductor and a neutral conductor. Therefore, in most cases, you will not be able to power the wall outlet from the switch, unless a cable with both wires at once fits to the switch.
If you are so critical of increasing the number of outlets, you can use tees and extension cords, they will increase the number of connection points and can disperse household electrical circuits.
In addition, it is allowed to lay electrical wiring in an open way along the outer surface of the walls. In this case, the line is connected to a junction box or mounted directly from the terminal board. To hide the cable and improve the interior design, they are installed in special cable channels.
Note, before starting the installation work, familiarize yourself with the wiring diagram in your apartment, so as not to damage the existing lines in the process.
I also want to draw your attention to the fact that the connection of the mounted electrical equipment is carried out only when the voltage is disconnected. Be sure to calculate the power of the connected devices, perhaps this number of sockets was designed for a certain load, and an increase in their number may lead to overheating electrical wiring.