Green’s Dictionary of Slang

jacket job n.

[SE (strait) jacket + job n.2 (2)]

something, or someone, liable to drive one crazy; thus mad, insane.

[UK]J. Cameron Vinnie Got Blown Away 70: Too much time thinking and you’re out of it. Jacket job.
[UK]J. Baker Shooting in the Dark (2002) 319: You’re a jacket job, you know that?