The Electric Fence is the same as a Fence, but is blue and when you are trying to cut it, it will electrocute you. (You will take 20 damage, and be sent to infirmary if knocked out.) They also extend downward a floor, posing an obstacle to digging escapes. Note that electric fences simply electrify the ground tiles beneath them. This means that the tiles below are not destroyed by cutting tools, but are simply dug through like any other ground tile. These tiles will electrocute you on contact as well.
In The Escapists 2, electric fences bear electric sparks and shock you if you get too near.