Old Scary Movie - Boy Sneaks Under a Hedge to a Big Creepy Mansion

I watched this movie in the early 80's so it is old.

All I know for sure is that it was a big mansion estate with a large yard surrounded in front by a boxwood hedge.  A boy goes under the hedge through a hole like a dog would dig to get under it and into the yard.  At the end, he is running from the house or someone in the house and dives under the hedge to get away and either runs off or stands to look at it.  I remember all this for sure.

I know the end was not happy.  He got away, but it felt ominous. 

The parts I am fuzzy on....

I am pretty sure it was black and white (we had a color tv) or it was an older lower budget that was filed darker

I think there were 2 kids at some point, but not a group.  One was a boy.  The other I am not sure.  I do not know if they both went inside together or if one found the other inside or if they both got out.

The house may have been crumbling or burning at the end, but not sure.  I just know he wanted away with no plan to return.

There was something sinister inside....maybe criminals and maybe ghosts, but the house was scary.

I think inside there was some sort of hidden stairs or something maybe in a basement.

It may have been early horror, but not typical 80s horror.  This was old and it was creepy/eerie, but gory or a overly far out sci fi. 

It felt British or UK or something, but I can't remember if there was any dialog at all.

I am not sure if it was a film, a tv show, or some sort of short film.  It would have been on daytime tv or a kid channel so likely one of those creepy shows/films in the 80s they aired for filler because it had a kid in it, but wasn't really a kid movie.  The vibe was very like Night of the Hunter, but it wasn't that.

It was not the shining and it wasn't a maze, just a hedge.

It also was not Haunted Mystery Mansion or Flowers in the Attic.  It wasn't modern and nothing well known or released in the theaters.  Please help.