A police box is a public telephone kiosk or callbox for the use of members of the police, or for members of the public to contact the police. Wikipedia

A type of public telephone Wikidata

A telephone kiosk where members of the public may telephone the police; a few original boxes still exist in Britain, but they do not operate. The city of Glasgow in Scotland has new police boxes, which are not booths but computerised kiosks, that connect the caller to a police CCTV control-room operator. Wiktionary