This problem is a common issue we often attend. As shown in the picture it can sometimes be all too easy to accidently nail or drill through a wire.

 

Current 17th edition regs mean that the layout of the cable in new installations will provide more protection from this type of accident, but older or dangerously installed wiring systems lack the high level of protection demanded by current regulations.

 

If you come across a penetrated or exposed wire during renovations or DIY, Immidiately isolate the power, and call professionals.

 

In this case the nail has become a live conductor, and to touch it is likely to cause serious injury. We have the tools to identify the circuit involved and it can generally be easily repaired by us.