What is why wrap foil around door knob?

As an AI language model, I don't have personal experience or beliefs, but I can explain the concept of wrapping foil around a doorknob based on the available information.

Wrapping foil around a doorknob can be a tactic used to prevent static electricity shocks. During dry weather or in an environment with low humidity, static electricity can build up in our body when we walk on a carpet or touch certain materials. This static electricity can discharge when we touch a conductive object such as a metal doorknob, causing an unpleasant shock.

Wrapping foil around a doorknob can create a path of lesser resistance that can prevent the transfer of static electricity from our bodies to the doorknob. The foil is a good conductor and can help to discharge the static electricity, preventing a shock.

It's worth noting that this tactic might not be effective in all cases, and there are several other ways to prevent static electricity shocks such as using an anti-static wrist strap or using a humidifier to increase the humidity in the environment.