There are high tension wires near where I live, and once in a while when the weather is good, I go hiking up there with my camera and sometimes, tripod. which is woven carbon fiber. (Its a Manfrotto knock off)
When unfolding the tripod or collapsing it, I can feel some tactile equivalent of a humming or something. This has never happened anywhere else.
Its a square woven carbon fiber.. the kind that look like a checkerboard or basket weave.. I have no idea what it is. Probably the electrical field.