New switch in lamp

[bigrez]

Hello - My neighbor just added a new 2-bulb ceiling lamp into an existing circuit. Everything work fine. Now, he added a 3amp switch to the lamp and when he turns the switch off, the circuit blows. The lamp works with the switch in the on position. Any clues as to what\\\'s going on?

Thanks!

 

[ban-all-sheds]

Yes - he's wired it wrongly...