Anytime I open my tube amp I'm EXTREMELY careful not to touch anything that I don't have to. I'll also never open it if I've played it in the past couple days, just to make sure that the caps are as drained as they can be (without me draining them myself).
They can definitely easily kill. I'd never open a TV, I have no problem opening up a tube amp, I'm just not familiar enough with the innards of a TV.