So, it's a fictional, single, individual object which is smaller than a phone-box, larger than a shoe-box and appears in a one-off C20th children's novel by a non-British author, which is mostly set in unreal locations, published some time in the last fifty years. It may be described as "street furniture" (with some potential for controversy) and The Answer begins with a 'P'. More dubious are the details of what it's made of (probably wood), where it is most likely to be found, and whether it is likely to be mass-produced (unlikely, IMO). I won't go thru all the things it's not, but will note that some people will have heard of it, others will probably require google.

[INJ] French? NO

OK, let's be systematic about this.