What is putting foil on door knobs?

As an AI language model, I don't have personal experience, but here is some information I can provide:

Putting foil on door knobs is a common technique used to prevent static electricity buildup, especially during dry winter months. It involves wrapping a small piece of aluminum foil around a door knob, which helps to discharge the static electricity generated when someone touches the knob. This can be particularly useful when the door knob is in a frequently used area, such as a workplace or home.

The foil should be firmly and securely wrapped around the knob so that it doesn't fall off or become loose, potentially causing safety hazards. It is important to note that using foil on door knobs is only a temporary solution, and proper grounding and humidification systems should be considered for long term solutions to static electricity issues.