[ He smiles thinly before looking down to hit the button that'll get the coffee machine started; it kicks in with a gurgle. ]

Spirits generally don't linger after death if they can help it. A few might stay to watch over loved ones, but most will pass on before too long. So for the ones that do stay ... it's usually resentment, anger, hatred that anchor them to the world. It warps their appearances as they become unable to remember anything other than those emotions.