What is a squinting modifier?
Modifiers are the words that add interest and depth to your writing. However, if not used properly, they can add confusion and even accidental hilarity.
A squinting modifier is one that could modify one of two words. Hence, it is unclear which word it is modifying.
He told her eventually he'd have to stop working: it is unclear if 'eventually' is modifying 'told' or 'stop'. Did he tell her after a long time, or will he eventually have to stop working?
Correcting a squinting modifier is simple. You just need to move the modifier closer to the word that it is modifying. e.g. He told her he'd eventually have to stop working.