Hidden Switches

Hidden switches allow you to hide a redstone lever or button behind a wall. On right click of the associated block, the lever or button will toggle. This feature was added in version 2.0.

Construction

Hidden switches consist of three parts:

1. A block to put the sign on.
2. Either a sign post or a wall sign with [X] as the second line.
3. A lever or button one block away from the sign in any right angle direction.

Right clicking a block next to the sign while not holding any item in your hand will toggle the switch(es) or button(s) adjacent to the sign.

In the configuration, it is possible to allow any face of the block to trigger the levers or buttons.

The other side... ideally you wouldn't use a different block type.

Using a "Key" to Further Restrict Access

You can enter an item-id in the first line of a sign to require the player to hold the specified item to be able to use the hidden switch (like a "key"). If the user does not hold this item, he will read that his key did not fit.

You can use almost any item in the game. To find the item id of any item in Minecraft, you can use this website: https://minecraft-ids.grahamedgecombe.com/

Note, that although the most recent versions of Minecraft have changed to a word-based verison of item ID's like "minecraft:itemName", the sign will still accept the old numerical id. So for example, "minecraft:redstone" is too long to fit on the sign, so you can use Redstone's numerical item ID "55".