Another way is socket/plug with IR remote control.You can decode IR signals from remote control and send it from arduino with an IR led.More easy and safe way no relays,no cables....AC 220 Volt is danger!!!If you think is difficult decode IR signals connect directly remote control with arduino.First the safe and your life and after your project.Inside arduino sketch you can put extra code for TV,Hi-fi,A/C and with bluetooth shield you can make all in one remote control for all your devices from android smartphone!No wires,no cables.
User ----> Android+Bluetooth------->Bluetooth shield+Arduino+IR led----->Send IR signals devices ( small local home automation )