This is probably a daft question so apologies in advance. I'm about to connect up an outside 300W security light and am considering where to take the power from. First I planned to loop into the house lighting circuit by adding a junction box to the supply to an existing light switch. However, on inspection, the wiring here is old, with no earth, and I'd prefer to have an earth if poss. Rather than re-wire the house I'm wondering about taking the power from the socket circuit, incorporating a wall-mounted fuse. I'd be grateful for any comments on whether this would be safe or legal. Thanks.