Shelly devices are designed to work with standard mechanical wall switches and push buttons.
In some installations, input behavior may become unstable when the device is connected to a wall switch that includes additional electronics — for example a built-in LED indicator, backlight, touch functionality, dimming circuit, or similar components.
This may lead to behavior such as:
Random switching ON or OFF;
Input being detected even when the switch is in the OFF position;
Unexpected input triggers;
Unstable operation after connecting the switch;
Lights or outputs reacting unexpectedly.
Why this happens
Some switches with built-in electronics allow a very small amount of current or voltage to pass through the circuit, even when the switch appears to be turned off.
For Shelly devices, this can sometimes look like an actual button press or switch action, causing the input state to change unexpectedly.
This does not indicate a defect in the Shelly device — it is typically caused by the type of switch being used and the way its internal electronics interact with the input.
Supported switch types
For reliable operation, we recommend using:
Standard mechanical toggle switches;
Standard mechanical push buttons (momentary switches);
Standard two-way or multi-way mechanical switches wired according to the official Shelly wiring diagram for the specific device.
Recommended solution
If you notice unstable input behavior, try replacing the existing wall switch with a standard mechanical switch or button that does not include LED indicators, backlighting, touch controls, dimming functionality, or other internal electronics.
After replacing the switch, review the Shelly input settings and confirm that the correct input type is selected.