I have removed an internal wall in my house, it contained all the electric cables for higher floors of the house. They are hanging down from ceiling to floor in the middle of the room at the minute and I'd like to move them to one side so they go down one of the remaining walls of the room. Unfortunately the cables are not long enough to do this, so I was thinking of cutting them and adding in another piece of cable to make them long enough. Does having a couple of joins in a cable present any risks (fire hazard etc), thanks.