There is a simple project I want to do for a long time. Turning my remote sound system on and off using ESP8266.
The materials required for this are as follows:

• Single channel relay card of LC Technology.
• IR Receiver VS1838 (I had removed it from another device before.)
  
• ESP-8266 Module

You install 1 ESP8266 module on the single channel relay card of LC Technology and you can control it remotely. 

This relay board has a STC15F104W microprocessor and communicates with 9600 bps 

If the card is original, it comes programmed, but if it is not original, you should program it. 

The company clearly wrote this on the site. If the light on the card is blinking continuously, the processor is without program. 

You can download the processor's program https://github.com/libretto/RelayMCU here.