Smart Home.

IOT is a fascinating thing. It helps us control "things" using simple voice commands or even an app which we can use from any part of the world. IOT is bringing us closer to a reality that we had seen in "Wall-E"(hopefully not too close). The entire guide as to how I built it is linked below.
https://www.instructables.com/Smart-Home-Using-Amazon-Alexa/

Breaf & idea.

The basic structure of the project consists of a device in our case the NodeMCU that connects to a server(Sinric) to send and receive commands. A Relay(s) is connected to the NodeMCU which is the device being controlled. The Relay in turn controls anything it is attatched to be it a Television, Fan, Light(s), and even heavy appliances like Air-Conditioners though keep in mind that the type of relay being used needs to be adjusted accordingly. We can use Alexa to control this relay using voice commands or even through the Alexa app.

“If you think that the internet has changed your life, think again. The Internet of Things is about to change it all over again!” — Brendan O’Brien

Result.

Since Alexa control has grown quite a lot you can even build a IR Thermostat using the same server. That will include temperature control along with monitoring the room temperature.