RULE 1, unless the voltage is very low it _can_ be
dangerous. Low is hard
number be exact about but, over 12-30V is the watch out zone.
RULE 2, All efforts are to be made to avoid crossing the heart or chest
as a possible path for safety. One hand in pocket rule is derived
RULE 3, if you not sure, make sure. get a meter and find out if it's live
and how hot hot is.
I just want to add a rule - Don't always trust what the meter says. I took
1950 v from an electron multiplier supply because the meter read around 40
volts. There was a common failure mode of this supply that it would shut
down to 40 v. Instead of walking around to shut it off before
disconnecting the meter (after all the supply was dead right? ) I just
disconnected the meter. Surprise the supply was good and the meter was
dead. I almost was also. I had severe cramps in that arm and shoulder for
almost 2 days.
Over the years working with RF and transmitters
I've been hit with RF and
DC to 1800V (ouch!) and LF AC power to 200V/400hz. Some were annoying,
a few painful, one nearly bluecrossed me and the better ones left scars
(and a willingness to NOT stick fingers in).