That sketch shows how to wire a switch with an external pulldown resistor. It is simpler to wire the switch using the internal pullup resistor.
It is just a wire from 5v to pin2, which is interrupted by a plastic part.
If the plastic piece falls out, the wire isn't interrupted, so electricity can flow.
Still have no idea what you are talking about. "just a wire" doesn't have any plastic pieces that can fall out.
And maybe a connecting instruction?
I don't know how much simpler it can get than "put one end of the switch in the digital pin and the other end in ground".
Now, it is your turn. Post a picture of this "just a wire" with "a plastic piece that falls out".