Combustible Material within boxes

[IBEW3NY]

Does anyone know if it’s a violation to mount plywood within any type of electrical boxes? I cannot find it in the NEC, but I may not be looking in the correct section. Any help would be appreciated..

 

[infinity]

Inside of an electrical box should be fine unless it contains an arc producing device.

110.18 Arcing Parts. Parts of electrical equipment that in ordinary operation produce arcs, sparks, flames, or molten
metal shall be enclosed or separated and isolated from all combustible material.

 

[fuzzysparky]

To be clear, you are asking about an electrical box and not a panel?