On Tuesday morning the actor sent out a warning along with a story about an upcoming auction in which a Luke Skywalker prop is to be to sold.

"Be Advised-There was no ONE lightsaber I used in the films, but many, MANY, both for myself & my stunt-double. Multiple duplicate back-up props are commonplace during production-When the handle ridges were cutting my hands, they even made a few w/ soft sponge ridges! #BuyerBeware," Hamill tweeted to his nearly 3 million followers.

Hamill said that while the lightsaber prop may be legit, it is not as rare as it may seem.

This is hardly the first time Hamill has looked out for his fans. The actor has been an outspoken crusader in the fight over fake autographs.

In fact, Hamill's efforts helped get a law on the books in California that any autographed item worth at least $5 must be accompanied by a certificate of authenticity, which must include the name and address of the dealer, date and purchase price and any third-party ownership. There was some pushback from dealers over the new law.

The Profiles in History Hollywood auction takes place Dec.11-13.

Hamill is currently filming Episode IX. J.J, Abrams is back in the director's chair for the installment, due out Dec. 20, 2019.

The full lightsaber auction item description reads:

Original production used Luke Skywalker lightsaber from 'Star Wars: Episode IV - A New Hope' from the collection of Oscar-winning set decorator Roger Christian who built all the original lightsabers for the first Star Wars film. (TCF, 1977) This lightsaber is consigned directly from Roger Christian, the original set decorator for 'Star Wars'. Included is a signed Letter of Authenticity from Christian stating the following: "As the Academy Award-winning set decorator for 'Star Wars: A New Hope', one of my responsibilities was to make the iconic Lightsaber for Luke Skywalker, the one below in the picture in Tunisia is one of them I created based on the Graflex flash handle. I handmade about five to use during the filming and the one you are buying is one of those used throughout the filming in London. This is the actual design of the Lightsaber from 'A New Hope', as presented to Luke by Obi Wan Kenobi as his Father’s weapon and part of my private collection. This original design had the bubble strip I placed in the clip, you can clearly see here and on the pictures below. Each lightsaber was handmade by me as Set Decorator, using whatever I could lay my hands on at the time to create the T-strip for the handle, the D-ring on the end and the bubble strip. My invention of creating the weapons, props and sets using real guns, scrap airplane parts and found objects gave 'Star Wars' the organic reality look for the first time in science fiction cinema. This Lightsaber below is one of the originals and it is authenticated as made by me, the maker of Luke’s Lightsaber, for which I won the Academy Award.