Product does not state indoor or out door use

This switch is not sealed to prevent any type of moisture from getting inside, be it running water, condensation or mist. Moisture of any kind inside "CAN" cause shock issues. Moisture inside WILL cause rust resulting in poor contact and lessening the life of switch. There are things that can be applied to the actual switch itself and where the wire/cable/etc. goes into switch which WILL make it water/moisture proof and safe. Electricians would know what I'm talking about. Sorry, I can't recall name but I have/do use it. It's 'gooey'. If you live in an area which gets a lot of fog I would make it water proof. Also if you place it where water runoff is likely. Hope this helps.

I have, wouldn't put it where it would be in the water or where it would get a great deal of rain, but in most cases, it'll be fine.

I use it on an outdoor driveway gate. I don't know if it was designed for outdoor use but it works so far.