Tesla Arc

The Tesla arc is a constructible settlement object in Fallout 4.

Gameplay
This trap is generally located on the ceiling inside buildings and looks like a large metal smoke alarm with electrodes protruding from its sides. Activation from a pressure plate or trip wire causes the trap to emit lightning bolts in random directions that will cause energy damage.

This occurs for a short period of time, after which the trap goes inactive and will not trigger again unless the location it is in is reset. This trap can be crafted at player-owned settlements.