Table lamps have a long cord you can cut off and attach it's contacts to a metallic door handle after plugging it into an outlet. Imagine someone grabbing it and you jump from around the corner with your finger-pistols doing ZAP-ZAP sounds at them as their hand locks in a deathgrip over a knob and their body does Bethesda ragdoll physics. And it's still not a prank.

The prank is: I put it up because this harmful and incorrect information is more likely to hurt the prankster than their victim.