What is this mystery cable in my new house?
You may find an unexplained cable coming down through a pantry ceiling or attached to an air handler after buying a house. Without clear labels, you are left stuck trying to figure out what the wire was originally used for.
What the numbers show
Counted from the threads quoted below. How we count
- People have been saying this in most months since September 2026.
What people tried
Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.
Found another way around this?
Share your steps and trade-offs so fellow engineers don't have to reinvent the wheel. No account required.
- 1Reading the writing on the black sheathingDid this help you?
- 2Checking broadband maps onlineDid this help you?
- 3Searching online or asking others on forumsDid this help you?
- 4Asking on a forum for identificationDid this help you?
- 5Ignoring it and using the included remote controlDid this help you?
In their words
Unedited, grouped by where they were said, most upvoted first within each place, each linked to the thread it came from.
“What is this cable coming down through the ceiling of my pantry/laundry room? Bought house last year.”source ↗
“Anyone know what this wire is for on mrcool cool 5th gen air handler?”source ↗
Where this came up
People with this problem also raised
- 7Unidentified mystery wires and cables in the yard after moving in
- 5How do I figure out what these HVAC control wires do?
- 3Is this outlet backstabbed or backwired?
- 2Software to map physical network cables from patch panels to switches
- 16Mystery part fell out during car repair — what is it?
- 2Hot and neutral wires connected together in ceiling box