Paddle Switch

[charlese]

My guess is the purpose of a junction box is to contain a spark that may occur with loose or moving wires in connections - then the fuse or circuit breaker throws.

In my last house, It was approved by a building inspector that I covered some wire runs (in the garage/shop) with wood tunnels. The wood also covered a couple junctions. This was in Southern CA/

[JPG]

First, there is not much other than insulation and splices that will burn inside a junction box.

Second a plastic(pvc) with a "VO" rating must self extinguish(when intentionally set on fire during a test) within 10 seconds.

Third getting the box itself to burn under normal conditions is unlikely.

Wood will not likely meet that.

Metal will hands down.

I am not a fan of plastic boxes, but they have their uses.

Sorta like the RMC,EMT,PVC preferences. RMC = pipe EMT = thinwall PVC = plastic.

Keep in mind arcing can start a fire.