Is a dimmer switch on the mini bot legal?

[ADTRavenger3585]

Hi, we withheld our minibot so we could finish putting it together and fixing it and someone had the idea to use a dimmer swith on the robot. I'm not going to assume that everyone who reads this knows what I mean by a dimmer switch. The one that my teammates picked out is one of the round ones that when you ouch it down it will turn off the light. Thinking the way I do I thought about the legality of the switch. Legal or not?