An adapter for mounting cable hangers to a mounting structure includes: a plurality of mounting panels, each mounting panel including a mounting hole, the mounting panels attached to each other at edges thereof, each mounting panel being disposed at an angle relative to its adjacent mounting panels; a base attached to the edge of endmost ones of the mounting panels; wherein the mounting panels and the base define an interior of the adapter; the adapter further comprising at least one pair of fingers extending into the interior of the adapter, each pair of fingers being configured to cooperate to grasp a cable.