Resident Demon(2004)

She found the secret to immortality... Death!

Resident Demon is a horror film about newlyweds who discover their first home comes with an uninvited supernatural tenant. The spirit haunting their house belongs to a female serial killer who died by suicide in the bathtub, surrounded by the blood of her victims. As the couple tries to settle into their dream home, they must confront the violent presence that refuses to leave. The film blends domestic drama with psychological horror, exploring what happens when the past refuses to stay buried and evil becomes impossible to ignore.