This is very easy. First you have to download the plug in named Optical Flares. It is used to apply lighting effects.
Then after installing the plug in, go layer and open a new Light layer. Make them surround in the back.
Then use Optical Flare to adjust the effects. Especially under the Flicker you can adjust the Speed and Amound.
This control the outcome of the lights.
Download Plug In:
How to install Optical Flare:
My practise outcome :