If you use 4’ tall 1" chicken wire that is grounded and run a couple of hot wires close but separated from that chicken wire on its outside charged with a steady shocker run from an outlet certainly stops squirrels in my experience. Pulsating shockers sometimes don’t happen to zap a swift squirrel and if they are starving they may even be willing to risk shock, but give up if they get shocked. Not sure about those details but I have made such a system work on sites where the squirrels removed green peaches every year without protection.
However, my customers vastly prefer running with my baffling method and I don’t quite understand why. Perhaps partially because I install baffles but don’t do fences.
Here’s a link to photos of baffles. They easily stop coons. DIY Squirrel Baffle ideas? - #24 by alan