Using a Contact sensor as a light switch?

Ooo, this is good. I have been hoping to find more, lesser expensive options for wireless buttons. Now that I have a few door/window sensors (with terminals) that I’m not immediately going to use as originally intended (i.e. instead using for other things like this and water/leak sensors, tilt sensors, etc), this may be a viable option for me.

So, do you think I could figure out a way to hook one of these up to a ‘normal’ wired wall switch, have this thing behind the switch in the wall, and have a wireless button for turning on/off a light?

If so, this is instantly less expensive than buying a Flic or similar. Not as nice and convenient, but still.


Never put a battery operated device inside a wall unless it is specifically designed for that, which most will not be. It’s a fire hazard.

You can surface mount it on a wall, which some people have done. ( if you want to put it inside a project box and then surface mount it, that’s usually OK as long as the box is not airtight and rated for this purpose. Many batteries outgas, which is part of the fire hazard problem.)

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Thanks again for rescuing me from ignorance, JD. :slight_smile:

Man, I gotta get out more.

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If the switch is not powered (dry), then the dry contacts in the contact sensor should register open / closed if wired across the switch. Just need to map “switch” capability to the Device Type Handler (instead of Contact).

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Thanks, Terry.
I suppose I could even just use a completely different DH for it…like, just use a switch DH for it instead of the contact DH. Right?

So, I guess the only stumbling block with my idea is the fact that I wouldn’t be able to mount it inside of the box in the wall, and would need to put it outside on the wall or something. I guess I will experiment with a couple things to see if there is any way of doing this without making my place look all whacked-out with boxes and wires all over every switch plate lol

(Replying to the box idea) I was considered doing this with a motion sensor in a wooden box with a hand sized opening like a VCR for some exterior lighting to eliminate the need for an outdoor switch.

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My OCD and my pain allergy would probably prevent me from doing anything like this outside. I can just see me sticking my hand up in there and getting bit or stung by something. lol Great idea though.

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By the way, an interesting variation on the sensor that wouldn’t have the fire safety issues is what some people do for a doorbell button: put a regular doorbell button on one side of the wall (or in this case A regular momentary light switch), run the wires all the way through the wall to the other side, and put the contact sensor on the other side.

For doorbell projects, people do this so that the radio doesn’t have to endure the outside weather. The contact sensor is indoors, the doorbell button is outdoors, everything should work fine.

For a light switch, you could put the contact sensor in a closet or just lower down on the wall behind some furniture.

So the switch/button looks like whatever you want it to look like, and the battery operated radio device is not inside a wall. :sunglasses:


Button on a box with a door switch inside…great idea too JD!

As long as the box is not airtight. Again, don’t put anything with batteries inside an airtight enclosure unless the device and batteries are specifically designed for that.

You could do a momentary or a toggle switch.

It’s not the type of switch that’s the problem in this particular set up, it’s having batteries inside an airtight enclosure.

But yes, in general you can have any kind of switch connected to a contact sensor so that you can use the radio in the contact sensor with SmartThings.

This is the same idea as the United pressure mat that people use. :sunglasses:

I’m clueless to the pressure mat. However, I did have pressure sensitive mats at my previous job at the Goodyear tire and rubber plant. The tire machine would not do certain things if you were standing on the pressure sensitive mat. Back to the door sensor idea, I would definitely have access to the radio/door sensor anyhow to be able to replace the batteries. Thanks for the great ideas.

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Pressure mat thread: