The basic idea of the in-game item is that it can reveal, suck, and blow enemies. It has a similar play feature shown on the back of the box:
It's worth noting that the backpack, vacuum, and flashlight are all non-functional. Once the Poltergust is activated, Luigi is able to jump on the yellow ghost. Without this mode activated, he would be scared of the ghost.
Activating this feature requires the user to press a button on the Poltergust pants element. How is this implemented?