Bell, Book and Candle by John Van Druten

Gillian Holroyd is a modern witch who can cast spells and perform supernatural feats. After casting a spell on Shepherd Henderson, an unattached publisher, he falls head over heels in love with her at once and wants to marry her. But witches, unfortunately, cannot fall in love, and this little snag leads into a number of difficulties. Ultimately, Gillian breaks with her fellow witches, preferring the normal and human love offered her by the attractive publisher. But before their happily ever after, Gillian comes very near to losing Shepherd.