How do I remotely check if a light is on without controlling it?

SONOFF and others like it allow you to control devices. But what to use for just checking remotely whether a light has been switched on? A simple key switch has to control this light and no automation can do it. I only want to be able to view whether it is on or off.

I don't want to construct anything. I prefer to use a ready-made one (although there may be some DIY version, re-soldering a contact, mounting in a housing). And of course it must "sense" 230V alternating. There is 230V power and network available at the intended location: Wi-Fi, ethernet over cable, and RF 433MHz.

Any ideas, suggestions?

Regards
Rafał Wysocki

In the FIBARO system you have SWITCH / WALL PLUG modules with power measurement - if the receiver is switched on, you see its current power consumption.

I've thought about that too. But this solution allows the PLUG to turn off the power. In addition, even if I leave it on and don't give anyone access, when the power goes out, when it comes back on, the plugs start as off by default. This shuts off the power permanently and the lights cannot be started with a normal switch. Unless, of course, you click in the app or on the remote control.

wysockr wrote:

plugs start as disabled by default

.
No, this is configurable.

I assumed they had the same as I was familiar with. I read the manual from them and they even have an "always on" mode. When they stop responding to remote attempts to switch off and to the button on the case. This turns the plug into an energy meter (“Always On” function turns the Wall Plug into a power and energy meter).

This is exactly what I mean. Thank you very much.