The Spirit of the Writing Medium Says She's Innocent

I'm the Pen Immortal. You ask what kind of Pen Immortal I am? Obviously, the one you already know. Probably because I can be summoned as long as someone has a pen, I keep popping up all over the place. In a way, I really am a ghost "Wait, not the kind of ghost you're thinking of! Hacking at me won't help!" Seeing the word "ghost" or hearing it, you immediately swung your knife at me. I clutched my head and dodged in a panic. Theme: Curiosity killed the cat