If it is there and shouldn't be it is a hallucination. Try to trust yourself about that. If you need to then you need to ask your husband if he hears the same thing (or someone else but late at night I assume your husband is closest).

Keep telling yourself "it is scary but not real". Write that down and look at it as much as you need.

Ask us on here. Like I said, I'm nearly certainly going to be on here until 2-3 AM. I don't fall asleep until then. I'm happy to provide reality checks as much as you need and I'm sure so are others.