I remember the first time I found a cache that was hidden in this way. I felt really weird searching in the lamppost. I remember looking around, circling it, then looking around again, and realizing exactly where it was, thinking I may get in trouble. Once I found my first one, I was amazed at how many of these types of caches there are around.
Anyway, this should be an easy one for experienced cachers, and if you are new, yes, it is in a weird space, and no, you won't get in trouble. Just be sure to watch out for muggles, as this is a high muggle area.