Two words that appear on many “frequently confused” lists are “elicit” and “illicit.”
Bryan A. Garner’s Modern American Usage says “illicit” misused for “elicit” attracted attention in the early 20th century, and cites a few examples (“The 43-point average of its star player illicits [read elicits] awe,” is one). But that misuse seems to occur rarely in news reports nowadays, if Nexis is any guide. (Garner’s most recent citation is from 2007.) And while “illicit” instead of “elicit” is listed at Stage 1 on Garner’s five-stage Language-Change Index (still a mortal sin), “elicit” is used in place of “illicit” so rarely, it’s not even on the radar of most usage authorities.
It should be hard to confuse them: To start with, they’re not the same part of speech. “Illicit” is always an adjective, meaning “not allowed by law, custom, rule,” Webster’s New World College Dictionary says. In other words: illegal. “Elicit” is always a verb, meaning “to draw forth,” as WNW says. (It has an obscure usage in philosophy as an adjective, meaning “Evolved immediately from an active power or quality,” The Oxford English Dictionary says, but unless you’re an ancient philosopher, you’ve never heard “elicit” used as an adjective.)
They don’t even have the same roots: “elicit” is from Latin “elicere,” “to draw forth,” and “illicit” is from the Latin “licitus,” or “lawful.” (“Licit” is a popular term in news reports, sometimes even where something simpler, like “legal,” might be preferred.)
In other words, maybe it’s hard to “elicit” an “illicit” usage.