Outside Light Question

[pathfinder]

I would like to install an outside light but am unsure of the wiring. In my ignorance am I correct in assuming that I can replace my existing downstairs hall light switch with a double switch and just run the cable from the outside light to the new double switch. Is it as simple as that ?

The hall light can also be operated from another switch at the bottom of the stairs. Does this mean that it is not as easy as just replacing the single switch with a double.

Any help would be greatly appreciated.

PS My apologies if this topic is a repeat but I have scoured the forum pages looking for an answer without any luck.

 

[Qedelec]

This topic has been cover many times before, but I will try and explain.

No its not just a matter of taking a feed fron the hall switch.
This will most likely have a 3 core and earth cable going to it and is unlikely to have a neutral.

If you can run another cable to this switch then I suggest you run this cable back to a Junction Box. Take a phase and neutral feed from a ceiling rose to the JB and the last cable from the light to the JB.

When you have got this far we can tell you how to wire it or you might like to look at the reference section.