Words like straitjacket and strait-laced are frequently misspelled using straight, which is incorrect, but understandable. Wouldn't a "straightjacket" be just the thing to straighten you up and straighten you out? Doesn't "straight-laced" aptly describe a person of refinement (the lace part) who lives the "straight life"? This is why some authorities accept straight-laced as an alternative spelling. But a strait is a narrow channel, and it is that sense of "confinement with little room to maneuver" that generated these terms.