… while the dial is intended to change the brightness of the light blub.
Thank you very much for your help, cheers.
No, that is a very bad idea!! It could burn your bulb or worse!
Thanks a lot for your quick reply. So that’s mean I need to change my wall switch all together.
Thank you once again 
Yes, it is because Yeelights have wifi always on, and lowering the voltage would simply mess something up. You can use regular switch though.
Exactly! Wall switch with dimmer not recommended.