A double tap is a when a circuit breaker designed to protect a single circuit is connected to two circuits instead.  As most homeowners never remove the cover of the electrical panel, this condition is often identified during a home inspection.

There are many breakers that are designed to protect multiple circuits so the presence of two wires attached to a breaker is not necessarily a problem.   These breakers have a slightly different design and have a designated space for each wire to be secured properly.

When the breaker is only designed for a single wire to be connected but two are added instead, the breaker can become overheated.  Loose connections are also a common problem with double taps.  These loose connections can lead to arcing, a dangerous condition with the potential to cause severe damage to persons and property.

Many times, the presence of double taps indicate that the panel size is insufficient for the electrical needs of the home.  There is also the possibility that the homeowner added a circuit and simply tapped into a breaker that was already present.

While the correction of a double tap is relatively simple and inexpensive, if this condition is present in your breaker panel, please contact a licensed electrician to evaluate the panel and correct the problem.

More detailed information regarding double tapped breakers can be found at https://inspectapedia.com/electric/Double-tapped-circuit-breakers.php