It sounds like a bad idea—I think I'd either end up with splinters or fall down a staircase and impale myself—but I have to admit there's an allure to a wooden necktie.
David and Chris are two guys from San Francisco who started up wooden tie company Wood Thumb. And they make them out of reclaimed lumber, so it's conceivable you could have a necktie made out of a railroad tie. They come in two sizes, and either will run you 34 bucks. I just wish the bottoms weren't so pointy.