They're not from a Falcon. They're 2 of the pegs from a Droid Factory, used to assemble various droids from the parts in the set, including the 3 Legged R2-D2. See top left in the pic below.
You don't know what they were doing in there? Why, they were waiting for you to find them! You're now not only the owner of a Millennium Falcon, you also own an incomplete Droid Factory ;-)