High Spirits (1988)
Edited from the LA Times, here's a synopsis:
An impoverished Lord, Peter Plunkett desperately tries to save his bankrupt patrimony by converting his castle into a ghostly theme
park with banshees on pulleys and servants under sheets.
Like you said, there were others at the castle:
Sharon, married to a charming nebbish Jack, is one of the customers on
the unveiling of Plunkett's haunts. The others include a yowling
parapsychologist, his flaky wife and a kitten-voiced sexpot, her eye
on a hapless Catholic novitiate.
Now the real fun begins:
The turn of the screwball here is that the castle is actually
haunted by a troubled 200-years-dead couple, trapped in a nightly
re-enactment of their murderous nuptials.
Jack meets and falls in love with one of the "real" ghosts, Mary. Here she is in "youthful" times:
After they spend the night together:
Read more about it here, here and here. Watch the movie here to confirm.
~ Screenshots taken from Wonder and Risk and TV Movie