Apologies in advance if this is a really stupid question, but I have been searching the web for some information and am hoping someone here can point me in the right direction for a definitive answer.

Can I use several characters from a 1945 classic motion picture in a book I am currently writing? In a nutshell, my main character has a couple of classic cinema icons living in her head and commenting on her life. These are not the actors that played the parts, but the actual written characters themselves.

Can I use them?

Thank you in advance for any help you might be able to give me!