This song goes by several names, mostly The Engineer's Child and The Red And Green Signal Lights, I think. It's proper name, though is Just Set A Light, words by Henry V. Neal, music by Gussie L. Davis, copyright 1896. This link should take you to the sheet music to JUST SET A LIGHT at The Lester S. Levy Collection of Sheet Music. When you get there, you will find a link to the next page at the bottom of the page.
I thought we had a discussion of this song earlier, but I could not find it without our Super Search. I KNOW we have talked about Gussie L. Davis, though, one of the foremost black composers of the period.