Is it allowed to turn off a fluorescent light during Bein Hashmashos in a room where I am sleeping when I didn’t have time to or forgot to before?
Should not be done. A non-Jew however may do Melochos during bein Hashmoshos for a mitzvah or in a case of great need. Sources: ההיתר דשבותים ביה״ש אינו שייך…