My 1,700 page supplemented American Edition (1854) of Liddell & Scott gives baskania as blame, baskanos as envious, slanderous and talebearing; and sums up baskaino (Paul's word in Galatians 3:1) as 'to use ill words of another - to slander or backbite'.
In profane use, the edition states that there was a meaning that strayed into the 'bewitch' 'spell' or 'evil eye' area but this does not appear (from this supplemented edition of Liddell & Scott) to be a primary meaning.
The concepts of envy, slander, tale-bearing and backbiting are (as the OP's comment suggests) very much in keeping with the activity of him who is described as a serpent and, particularly I would say, in keeping with the meaning of diabolos - slanderer. (Dia-bolos, through entanglement - as with the bolos fishing net.)
Thus it appears in Galatians 3:1 that Paul is asking 'Who has, through envy and slander, misled you from the pure gospel ?'
He then makes this clear by saying 'that ye should not obey the truth'. It is their obedience to truth that has been affected. They are not cowering in fear of some spooky 'evil eye' or weird 'curse'. What Paul is addressing is that the Galatian Christians have hearkened to slanderous lies and been moved from their steadfast following of gospel doctrine.
Further, he remonstrates with them 'before whose eyes Jesus Christ has been evidently set forth (in preaching) crucified among you'.
Before their very eyes, by the preaching of Paul, these Galatians had 'seen' (by faith) the crucified Saviour. But now, by envy, by slander, by other words of untruth, they are moved out of the path and need to be recovered from a parallel path which, if followed, will diverge more and more in legality.
They were not diverted to weirdness by an evil eye - to follow strange rituals or to become idolatrous lunatics. They were subtly misled by false statements (close to truth but not true) to turn back, from believing in Jesus Christ to be perfected (supposedly) by the Law of Moses !
The translators have evidently struggled to convey baskaino with one English word. 'Bewitch' is perhaps not exactly the meaning which Paul had in his inspired mind.
'Divert' ? 'Mislead' ? Possibly.
Foolish as these Christians had been, I do not think that they were altogether stupid and superstitious enough to fall foul of a wandering, hocus-pocus conjurer. They had been diverted from truth by that which often diverts from truth - something close to truth but which is not, exactly, truth . . .
. . . just as the serpent in Eden used half-truth, innuendo and slander to divert Eve from the right way, as the OP states in comment.