Bathroom extractor Fan?

Hi there, first of all Can I just say I will try my best to give a prompt reply to this,

I have recently installed a fan in my bathroom due to mould on the ceiling, now first of all my bathroom is extended and due to the roof being flat I was unable to fish the four core cable over to my bathroom light I literally had tried everything so instead I have wired it down into my kitchen light with 1.5 white flex (twin and earth so the fan is constantly on but only trickling

So the wiring into the kitchen light is bang on but I was just wondering is this is safe, just after a secondary opinion

Replys will be muchly appreciated!