Ariana Dumbledore is another ghostly character in Harry Potter, although in her case she isn't so much a ghost as an apparition. The character died as a child, although she appears to Harry as a fully-grown woman in a moving portrait and has quite the mesmeric effect on the young wizard.
Being little more than a painting, the character didn't get any lines, which was a shame for actor Hebe Beardsall. She seemed to struggle to find work for a couple of years after her Harry Potter appearance, but a spate of British TV appearances during 2017 have nudged her career in the right direction, and she recently received a great deal of acclaim for her work in the movie "Funny Cow". A recent newspaper article noted that acting doesn't yet pay all the bills for her, and she has a day job as a children's entertainer.