A sticky lighting problem

[snevets]

I've recently moved into a house built in 1969. I'm fairly competent around the house with electrics and plumbing and stuff but recently came across something that has me stumped.

I have a standard 2-way switched hallway light that can be operated by either one of two single switches at opposite ends of the hall. When I moved in it was obvious that the switches were wired wrongly (i.e. you could only switch the light on with whichever switch you used to turn the light off) so I decided to check it out. I wont go into the comedy wiring set up that I found, suffice to say that I was amazed that the light worked at all and that the house hadn't burned down - I also decided that the 'static' shocks I was getting in the hall probably weren't down to the cheap, nylon carpet!

Anyhow, I sorted out the wiring and all is well...only when fixing the problem I noticed that the exposed parts of the Cables seemed to have a sticky dark substance on them (a bit like diluted tar I guess). I checked other lighting switches and roses around the house and found the same thing. Like I say, the circuit works fine but I am confused/a little worried about the sticky stuff as I've never seen it before in any house I've been in. Is it possible that the dodgy wiring generated heat that melted the insides of the cable sleeves or something like that and/or is this anything to worry about?

I've done quite a bit of checking around and have got nowhere with this so any help/ideas are much appreciated.

 

[breezer]

If the cables had been over heated then there would be black burn marks that would be "crispy" if the substance you have is sticky i would suggest that it is or was what is left of the old type of insulation tape, it also sounds like it is breaking down through old age, i would do what you can to remove it and use proper connections / sleaving

 

[snevets]

I wondered the same about the insulating tape theory but the sticky stuff can be found on the cables in the switches, roses and junction boxes - and there seems to be too much of it to have come from tape (I found two reasonable sized blobs of it on top of one ceiling rose). Thanks for the reply though.

 

[loftus75]

Many years ago when wiring houses in plastic conduit, some electricians used to use washing up liquid to ease the wires through the conduit, I would imagine if a residue remained it would look pretty black by now and would probably have some viscosity (stickyness). Just a thought.

 

[snevets]

That would make sense as the house is wired through plastic conduit - thanks.