To add to what Cranky has said, I have used Finolex 7/20 cables with Fire Retardant capabilities throught my house. This was done about 15 years ago. The ends are still shining copper whenever I have opened a few boxes to change a switch or a socket. I have used MK wall plates, switches and sockets throughout. I have had no issues with these cables. Excessive power drawing or a short in some equipment would immediately result in a trip in my mains junction box. Nothing would happen to the unit or to the cables.
Cheers