Thieves put lives in danger after stealing more than 1,000 metres of live power cables near Knottingley.
In one incident, Northern Powergrid said homes around the town were left without power for 12 hours after cables carrying 11,000 volts of electricity were stolen on April 30.
The thieves left the cables hanging down just above a footpath used by dog walkers near Cridling Stubbs.
Live cables were also left hanging just above a road used by lorries in a separate incident near Goole last month.
Nigel Walker, vulnerable assets manager at Northern Powergrid said: “Once again, thieves are showing callous disregard for people’s safety as they target the power network to steal cable with relatively little financial value.
“The consequences of leaving cut electricity cables carrying thousands of volts hanging dangerously close to a public footpath doesn’t bear thinking about.
“Anyone touching these cables to simply try and move them out of the way would have suffered very serious injury or worse.”
Mr Walker urged people to be vigilant and if they see any suspicious activity around the area to report it to the police or Crimestoppers.