Need a lighting circuit gizmo but can't find the right terms...

Ok, I’m looking for two lighting specific wiring solutions for my new Tacoma. First, I’ve seen a gizmo discussed on the forums that clips around a headlight wire and can sense when juice is going to that circuit, thereby allowing another bit of lighting to come on automatically when you headlights go on. For the life of me I can’t find those topics, nor can I manage to put together the correct search terms for Google to find it. Second, I’m looking for a way to similarly sense when any of the doors are open, so I can engage a kick panel light to help my parents from smashing their shins on my steps. Does anybody have a tested method of tapping into the dome light circuit?

Thanks

 

Sounds like you need a relay?

 

Are you talking about T-taps or posi-taps?

 

Don't cut wires or use crimp on taps.

 

Simpleton: yes, a relay would be part of that circuit, triggered by the presence of voltage on the main headlight lead. the gizmo i saw was a packaged add-a-fuse, relay and T-tap all in one.