Using a lock as a Contact item

Up until recently, I’ve used my smart lock as a Switch item, but I just saw that Contact items are fit more for this role.
I could control the lock from the paper UI using the Switch type, but when I edited the lock’s item type to be Contact, there wouldn’t be a control button/switch in the UI, or it would just show NULL.
Why isn’t it working? Do I have to do anything else?


A contact is non-controllable so not sure why you think it’s more appropriate than a switch? You would never be able to control it from OH, only get status.

That would be a contact should only show its state, while a switch should actually change the state. That is the difference between both types!

It’s way clearer now!
In the docs, I just saw Can be used for sensors that return an "open" or "close" as a state. This is useful for doors, windows, etc. so I thought I should use it.

In this context a lock is not (just) a sensor, it is an actuator.