Street lights full of ant nests, and others with their electricity supply being illegally diverted have been discovered during an inspection across Northampton.
The review has been carried out on behalf of Northampton Borough Council taking in most of the 1,300 lights it owns, and has so far found that more than 300 needed some degree of work.
Many have been branded unsafe either because pieces were precariously balanced or wiring was dangerously exposed.
Deputy leader of the council Phil Larratt (Con, East Hunsbury) said contractors Thorn Electricals made some surprising finds on their rounds.
He said: "Some have the heads dangling by a just a wire, and others had doors missing with exposed electrics. One had an ant nest in it.
"With another, someone actually fixed an extension lead to one of the lighting columns in order to steal the electricity. They used a Stanley knife blade as a fuse."
A report to councillors on the borough's overview and scrutiny committee said the significant amount of work needed was due to "a poor maintenance regime in the past."
Areas that will benefit from the work, which will cost about £900,000 when complete, include Bradlaugh Fields, the Racecourse and paths alongside the River Nene.
So-called 'heritage lights' such as those outside the Guildhall are also being reviewed.
Any replacement lights are set to use less energy and require lower maintenance costs.
Councillor Larratt said: "We just want columns that are safe, and lighting that's effective, efficient and fit for purpose.
"This needs to be worked into the council's next budget. But safety issues like this are a priority."
Assuming the funds are approved, repairs will begin in early April 2019.