Humberside Police are appealing for witnesses and to recover stolen jackets which could be used to commit crime.
The BT exchange on Scawby Road in Brigg was the subject of a burglary between 5.30pm on August 21 and 7.30am on 22 August.
Intruders climbed over the perimeter fence and forced the locks on two vehicles parked securely in the yard.
Four Hi-Viz jackets (as pictured) were stolen.
A spokesman said: “We are concerned that these jackets may be used by the thieves to commit further crimes, such as bogus calls to homes affecting vulnerable residents who may be duped into thinking they are genuine BT workers.
“If you know anything about this burglary or have information about the jackets stolen, please call us on the non-emergency number 101 quoting reference 16/32385/17.
“Please be aware of anyone cold-calling at your home. May sure you ask for photographic ID and if there is any doubt about their identity please call the company they are representing to make sure they are legitimate workers.”