The bodys electricity can be detected or measured, but so can your heartbeat. Do you know anyone who can control their heartbeat? I don't mean stay calm- have you ever heard of anybody who can decide "I'll change the speed of my heartbeat" and consciously do it?
Yes. Not only is it common to find such levels of conscious control over "involuntary processes" among the adept in yoga, it can also be found among the "psychopaths", a particular and uncommon subset of the antisocial personality.
BTW, it is also possible to train to develop conscious control over one's serum oxygen saturation, metabolism, and (gasp) breathing. These are things being done in research on chronic pain treatment, status post coronary artery bypass graft surgeries and some seizure disorders.