You're in the wrong forum for this, but seeing as you have a 1 post count, that makes
sense.
A lot of box builders use 10amp horn switches. They seem to work for most box mods, even the 8V, 400W+ LiPo boxes on Vaperzcloud.
I'm personally using a 230W-capable jet-ski starter solenoid for my 4x18650 parallel box, just for the fun of it going
CHUNK
CLANK


CLANK
CHUNK
and that I don't need a secondary circuit with ballast to stop the horn switch from melting.
You could also take a switch from an existing tube
mod and attempt to solder wires to it...
Just kidding don't try that.