Using a selection type item

Not like this.

The example as written will, for example, set the LR_TV_Channel Number Item to 1 if the user selects “BBC One” from the list.

You have separate Switch Items for each channel. Selection does not work with multiple Items.

You will need to create a Design Pattern: Proxy Item as a Number Item and a Rule to send the ON command to the right Item based on the number it gets commanded with.