We have a wired smoke alarm system. We've lived here 9 years and I have no idea if they work or not, so I installed battery-operated ones in pretty much every room.

One day the wired one upstairs was going off for no reason. It didn't even sound normal - it sounded like it was going out. So I pulled it off and detached it from the clip.

I want to find a cap to put over it to plug the hole but I'm wondering what to do with the wires. The orange/red wire is just hanging and the white and black wires are attached to the clip that went into the alarm.

Pic of alarm wires

1 Answer 1


Stuff the wires in the hole and put a round blank cover over it

Hardwired smoke alarms, like your old ones, are required to be mounted to mains wiring junction boxes since they run directly off mains electricity, and all splices of or connections to mains electrical wiring in North American need to be made in a junction box. As a result of this, what you're seeing here is that junction box, and junction boxes can't be left open/uncovered, so you need to put a blank cover of the appropriate shape (a 4" round cover should do the trick) on the box the smoke alarm was mounted to.

  • I'm very novice and don't know all of the terms you're using; which is why I was unable to just search & read about this online. Are you saying to just cover it? I don't see what box or junction you're talking about. Thank you
    – user126673
    Dec 5, 2020 at 19:58
  • 1
    @user126673 -- I'm saying to cover it with the correct thing -- a 4" round blank cover is what you need, and it will come with screws that go into matching holes in the box to attach it. You cannot cover it with building finish materials, as that makes it impossible for the next bloke to find it, never mind actually getting into it to service the wiring inside Dec 5, 2020 at 21:00
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    TPE, you don't really address how to deal with the wire terminations. OP should probably clip off the old connectors and install wire nuts.
    – isherwood
    Jan 7, 2021 at 14:43
  • @isherwood -- my line of thought was "whoever uses this box next to wire something can deal with the connector, the OP just wants things over and done with" Jan 8, 2021 at 0:15
  • But there are currently uncapped wires, right?
    – isherwood
    Jan 8, 2021 at 14:00

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