A plug-in point adapter provides a self-contained adapter assembly that may be plugged into the connector jack of an existing electrical alligator clip probe and which increases the length of the probe. In some implementations, the adapter includes a test point that can be projected forward to a selectable length between the jaws of the clip that allows the clip to be used either as the point of a test probe or the original service as an alligator probe. In some implementations, the adapter transfers the alligator jack to the adapter jack for connection of the test lead plug. In some implementations, the adapter latches to the alligator clip and remains on permanently. The original alligator clip is not modified in any way and therefore the adapter can be customized for various designs of alligator clips that do not have to be modified.