3 ms·It is electric, and it happens when you're on ungrounded AC.by stouset 3y agoIt is electric, and it happens when you're on ungrounded AC.ggm 3y agoThe write ups I've read said it was a microvibration on the board, not leakage into you. Its origin is electric no matter what.stouset 3y agoIt’s leakage current. Again, it only happens when ungrounded.jve 3y agoAnd happens also on multiple DELL laptops I used/touched.