List the email of customers that bought the book titled Switch on the Night.
"Switch on the Night" is the title
SELECT T4.email FROM book AS T1 INNER JOIN order_line AS T2 ON T1.book_id = T2.book_id INNER JOIN cust_order AS T3 ON T3.order_id = T2.order_id INNER JOIN customer AS T4 ON T4.customer_id = T3.customer_id WHERE T1.title = 'Switch on the Night'