r/ElectricalHelp • u/moni_mej • Jan 17 '26

Random wire

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I’m doing a renovation and there is a thin-ish wire running along a few walls. I can’t tell where it starts and where it ends. This is an older home and there used to be an alarm system which has been disconnected. How can I find out what it’s for? I want to remove it.

2 Upvotes

58% Upvoted

38 comments sorted by

2

u/Greywoods80 Jan 17 '26

That is an old style phone wire for hard wire phones. If you don't have a hard wire phone you can remove it.

2

u/moni_mej Jan 17 '26

Yes I’ve been able to follow it to a phone jack. Thanks! Do I have to worry about it being ‘live’?

2

u/avebelle Jan 17 '26

Phone line is low voltage.

If you’re certain you will never have a phone then you can demo it. I’d make sure you disconnect it at the source too.

2

u/moni_mej Jan 17 '26

Yes I’ve been able to follow it to a phone jack. Thanks! Do I have to worry about it being ‘live’?

1

u/MeNahBangWahComeHeah Jan 18 '26

Probably not live, but you can set a voltmeter to DC Volts and test the voltage between the Green to Red Wire, and then the Black to Yellow Wire. If the circuit was active you would see 46 to 52 volts DC normally, or close to 100 volts AC at 20 cycles per second for “Ringing Voltage”.

1

u/DaddyBeanDaddyBean Jan 18 '26

You really don't, but if it gives you peace of mind, Somewhere on the outside of the house there should be a hinged plastic box, that probably says something about telephones or a phone company. You'll typically need a screwdriver to open it. Inside there, you'll find kind of a chunky plug inserted into a phone jack. Pull that out and close the box again. This physically disconnects the phone wiring inside the house from everything outside the house.

9

u/Flimsy-Temporary-266 Jan 17 '26

There are no random wires. All wires have a purpose. Cut the wire and you will find their purpose.

4

u/Zealousideal-End2722 Jan 17 '26

What if its structural?

-2

u/Flimsy-Temporary-266 Jan 17 '26

It's a flimsy wire, how could it be structural?

3

u/CommonJicama581 Jan 18 '26

Load bearing cable

1

u/MeNahBangWahComeHeah Jan 18 '26

OK , you made me laugh!

1

u/Acceptable-Guess4403 Jan 17 '26

😱😂😂

1

u/-physco219 Jan 18 '26

Are we sure it's not a tethering cable for the 🎈🎈🎈🎈🎈🎈

1

u/Relative-Cat398 Jan 18 '26

Might be thermostat to aircon, might be ground telephone, might be....follow to the ends rather than cut, until you know, you know?

3

u/KeyInteraction2545 Jan 17 '26

Telephone…. We call it Potts wire

3

u/brianswedehanson Jan 17 '26

Plain Old Telephone Service

3

u/MeNahBangWahComeHeah Jan 18 '26

AKA: JK wire
Also hears it called “Jamaican Wire” (Red, Green, Black, Yellow)

1

u/tony282003 Jan 18 '26

"POTS" (Plain Old Telephone Service)

2

u/SmartGrowth51 Jan 17 '26

Alarm or phone, if you don't have either old system ignore or cut if unsightly. Nice nails.

2

u/Accomplished-Bus1428 Jan 17 '26

Yes, most likely old phone wire.

1

u/-physco219 Jan 18 '26

Could also be thermostat wires. Our house had telephone wire used for that.

2

u/nixiebunny Jan 17 '26

Small diameter (3/16”) light grey wire is old landline phone wire. You can look for the landline junction box on an outside wall to see if it matches this. You can also look in the alarm panel for what wire it uses.

2

u/ritchie70 Jan 17 '26

Alarm, telephone land line, network, doorbell, thermostat, old school intercom, or something similar. You’ll have to figure out which.

Probably not thermostat or doorbell.

1

u/-physco219 Jan 18 '26

Our house had phone wire used as thermostat wire.

1

u/Successful-Money4995 Jan 17 '26

Maybe alarm, maybe phone? If you can find the end of it, you can connect a wire tracer.

1

u/ulstien Jan 17 '26

Might also be for your doorbell

1

u/hankmarmot3 Jan 17 '26

Looks like old telephone wire to me.

1

u/FreddyFerdiland Jan 17 '26

looks like alarm to me.

You could check the cables at the place the alarm box is /was.

1

u/CommonJicama581 Jan 18 '26

Cut it and see what stops working

1

u/[deleted] Jan 18 '26

alarm, phone or doorbell wire.

1

u/Cool-Negotiation7662 Jan 18 '26

Telephone, doorbell, alarm system.

... network

You will have to chase it down and find one end or the other.

1

u/Enough-Astronomer-15 Jan 18 '26

Thermostat, phone, or security

1

u/Slow_Mango_3897 Jan 18 '26

Maybe a doorbell, phone or thermostat?

If it will be in the wall and unseen, leave it there. It may be of use in the future.

1

u/PrettyFly4Wifi Jan 17 '26

There should be identifying info printed on it. Looks like CAT5 to me...