A red-light district is read symbolically as desire, temptation and the parts of life kept in the shadows. Dream books treat it as a question about what you want and what you judge in yourself, without condemning the dreamer.
Has this come up in your dreams before? What was going on in your life then?
My Cosmic Code has a private dream journal. Write a dream down and the app picks out the symbols in it, shows what dream books say about them and, over time, which words recur across your entries. The journal is stored on your device only.