i get an electric shock

Yesterday i havd repairing my projector,ha get some thing bite my hand and a get very pain,through my hand into body,i wave my hand as fast as immediately.
I knew it's my fault repair projector without not cut off power.i get an electric shock.

I'm very lucky the electric can't hurt me,but it's very dangerous thing for people,never foget cut off the projector power befor repair it.