Take a look at your electrical panel. A double tap occurs when two wires are connected to a circuit. This is one of the top 5 causes of house fires in the U.S.

What problem do you think is going on in this picture? The problem here is exposed combustible insulation. Insulation installed in any interior spaces including basements, crawlspaces, garages or any other interior spaces should be covered drywall, other interior finishes, or wood paneling (acceptable in most areas).