The phrase 'closet witches' is actually more of a modern cultural term than a specific book title, but it seems like you're asking about 'The Closet Witch' or maybe stories featuring witches in hiding. If we're talking about Sabrina Spellman from 'The Chilling Adventures of Sabrina' or the concept in general, it's a mix.
A lot of these narratives borrow surface elements from real traditions—like Wiccan holidays (Sabbats), moon phases, herb lore, and the Rule of Three—but they're heavily fictionalized for drama. The 'closet' aspect, hiding powers from a non-magical world, is almost purely a narrative device from urban fantasy and coming-of-age stories. It creates conflict but isn't really a cornerstone of most real-life witchcraft practices, which are often about personal spirituality and community, not secrecy from normal society.
Where you might see overlap is in the use of protective symbols, candle magic, or kitchen witchcraft, which some modern practitioners do incorporate into daily life discreetly. But the dramatic, hidden-identity plots full of near-exposure and magical showdowns? That's straight from the fiction shelf.