Light activate with Arduino Home Controller without use of relays and cables, only using wifi, with this little module based in Wemos D1.

My Arduino Home Controller activated by Alexa initial project, see in this Url, let us connect some devices to Internet and control thems using Amazon Alexa Skill.
If you need control some lights, you needed connect each bulb socket to each relay, but if you need control remote light rooms and we don't use cables only using wifi, you could make this project.

Using Wemos D1, or any other type of ESP8266, you can create some accessories and connect them to our controller using wifi network.
This accessory reemplace the light interrupt present in the wall with all necessary to turn on or off any bulb from 10 Watts to 100 Watts.