Taping into and Installing outside security light

Hello I’m looking to install a new security light at front of house. Where I’m drilling it would end up in small toilet at front of house. I’m looking for any advice on how to fish the cable from small toilet to a light switch on the outside of the toilet but would be looking to take it over a door frame and then if it is possible tap into double light switch for the small toilet and hall light. I’m obviously wanting the cable all hidden. If it’s possible to tap into double light switch would I then need to make it a triple light switch (one switch to be on constantly to power the security light?) and would the cable behind plaster board and in the insulation need any type of protection? And does the cable I use need to be a minimum kind of length? Any help would be great thanks 

Is there a neutral ,at the switch?.....if not then it won't work anyway

an 'electrician' I know tried exactly the same thing and ended up taking 5 lights back saying they were faulty  msl1:

Make the length long enough to reach from switch to light?????

Hi yes it has a neutral, it also has 4 cables coming into it but it only powers 2 lights  :facepalm: ?

I though I read somewhere linking cables had to be a certain length? I’m not entirely sure was only asking for a second opinion and wee bit of help, so a linking cable can be any length? At most I’d probably only need around 2.5m anyway but was just double checking this was ok? 

Paul 1982 said:

Hi yes it has a neutral, it also has 4 cables coming into it but it only powers 2 lights  :facepalm: ?

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Welcome to the forum.

Please be careful with electricity it can kill a health adult in fractions of a second.

That said, please also realise that just because there is a black or blue coloured core in the switch, it is not necessarily a neutral.

The house is 15 years old and the blacks are all bunched together in a plastic terminal block. There’s 4 cables, I’m assuming ones the main feed coming from consumer box then one linking to feed toilet then one linking to feed the hall light, just wondering where the 4 one could be coming from 

Paul 1982 said:

... could be coming from 

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Or going to?...

Yes, so would you reckon one is defiantly coming straight from consumer box then 2 powering toilet and hall then the 4th linking to maybe my livingroom light? Only really want to know if it’s possible to tap into the light switch for security light,

thanks again 

And if it’s relativly easy to do with the power of. Is it safe to run a piece of cable behind plaster board with no protection ?

Could anyone tell me if I can tap into my light switch for security light, it has a live neutral and earth

  :signthankspin:

probably

Paul can you post a pic of the inside of this switch, it will make the help you receive easier and more accurate. 

Yes sharpend I will do thanks. I’ll try get it up next few hours thanks 

if the blakcs are in  bit of connector block behind the switch plate, then chances are you have a nuetral at the switch.

there is no minimum length for the cable, not heard that one before! 

Thanks binky, there are blacks bunched together. Trying to get my pictures smaller in size to post atm 

. 

Q: is that back box on a brick/block wall or timber stud wall? 

Ideally you could do with box being sunk deeper into wall as three gang switch gets a little tight for space. 

If you don't want the security light switched then you may be ok. 

I think that the "length limit" younare referring to,could be related to the cabling restraints involved with the old style 'low voltage' lights. I.e. 12V 50Watt dichroic spots

the uninitiated did not realise they may have been 12 V BUT they were 5Amps a piece

 connect 6 together on a bit of 1mm ( or worse still use bell wire...after all its only 12V! What's the worst...) and say hello to Trumpton

The back box is in a stud wall, it does sit flush just needs tightened slightly. 

Im not wanting a switch for the light, just want a live feed to it all the time so when someone approaches it comes on. 

Do you know what I should wire it into for that to happen? Earth to earth neutral into the blacks what part would the live go into?

Not the switched side!