help needed on extending a cable for a light switch

[thepollynator]

hi guys just a quick 1 ,
I've just re decorated a bedroom and brought new light switches , when i removed the old one i found that the cables had been pulled tight making it virtualy impossible to fit new switch grghhh . is it possible to join the cable a little bit and hide it behind the facia maybe ? any advice would be great but re chasing the cable aint happenin as ive just decorated lol
stu

 

[Spark123]

You can extend the wires using a couple of pieces of terminal block housed in the backbox and some new wire of the same diameter as the original.

 

[thepollynator]

excellent thank you i think ive done something similar with some speakers before could not remember what the parts were called
cheers
stu