Vandals who left live wiring exposed when they tampered with street lights in Nottinghamshire, "could have killed someone", said police.
The panels on five lamp posts in Knapp Avenue, Eastwood, were removed by someone with electrical expertise, according to officers.
They were then replaced, but with the wires left hanging out of the front.
The damage on Wednesday night, which was later repaired, interrupted the electricity supply to several houses.
Sgt Auslin Duggins said: "This is a very unusual incident indeed and I am at a loss as to why someone would want to cause this sort of damage with apparently nothing to gain.
"The front panels of the lampposts had been taken off and then reattached but left extremely dangerous, live wires exposed.
"This could have killed someone and I would urge anyone who knows who did this to get in touch to ensure this does not happen again.
"If anyone sees anything similar anywhere else, I would urge people to stay well away from any exposed wires and call the police immediately so that we can make the area safe."