Looking for a Book About Supernatural Feng Shui and Ghost-Hunting

I read a book a long time ago. In the first chapter, the heroine was already catching ghosts. I think it was a seductive female ghost, and it was in the hero's room. The heroine went to catch it, but the hero misunderstood and thought she'd come to sell herself. She called him Uncle, and she was very innocent. That's all I remember.