I am installing an outside light near an internal 2 way switch. Can I take a feed from this without preventing the 2-way switch working? If the answer is yes then where should I go for a wiring circuit?[b][/b]
almost certainly not as it is very unlikely there will be a Neutral at the switch. Any wires no matter what colour that are connected to the switch will not be Neutrals.
If there are by chance some Neutrals in switch box they will be in a seperate connector at the back of the box not connected to the switch