I think it says Mur g, which could be short for bricklayer journeyman. He lives with Master bricklayer Olsson before he moves. Second to the bottom of the page (https://sok.riksarkivet.se/bildvisning/C0067147_00264)
/Peppe
Oh, right, that makes sense! He is indeed mentioned as being a bricklayer later on in the sources, but nice to know he was already one before leaving home and to know where he was taught. Thank you so much!