Give your child things to do to help with the fear. Let your child turn on a nightlight or flashlight. Then your child can make the room not so dark and not so scary. Let your child turn on the vacuum cleaner to be in charge of the noise. Ask your child to turn off a tv show that is scary.
Children can feel powerful when they turn it off.
Children do not know what is real and what is not real. Your child needs your help to learn what is real and what is pretend. Many children need to hear again and again that monsters are not real. There are many books that help children with fears. Talk about what is not real in the book.