On 16 Oct 2017 18:03:10 GMT, KenK wrote:

Do they make a gadget that detects the presence - not necessarily flow - of
electricity in a conductor through insulation, walls, etc? Not electric
flow because I am hunting an open circuit in a mobile home. I want to see
how far the power is getting without removing caps on splices, opening
walls, etc.

TIA
Non Contact voltage detectors do exist and they do not require
current flow. Most have a pretty limitted range (you can check a wire
without disconnecting it, but you need to get into the box or into the
wall)
Some "stud finders" have a "live wire detector" built in as well.
Otherwize you need to disconnect the power and use a "fox and hound"
tester - but a bad connection can often still pass enough signal to
fool you.