My parents were married for about two years at the time of this incident. The two-bedroom house they stayed in used to belong to my mother's step-father who left it to her in his will. It was known as a semi-detached house.
The piece of land next to the house was large enough to build a second house. The grass was never watered because there was a natural underground stream. All my dad had to do was mow the lawn!
The walk from the main gate to the back of the house was quite a long one. The ground sloped somewhat, which meant that there were three high steps to climb before entering the kitchen. The back door was a stable door.
Most of the time the bottom half was left closed while the top half remained open.
If you stood on the top step looking over the bottom part of the door, you would be able to see the person inside at 'eye-level.' But if you stood on the ground outside, you would not be able to see inside the kitchen, even if you were tall.
One day my dad was chatting to my mom while she was preparing their meal. He was standing with his back facing the door. There was a knock and both parents turned to see a black man who asked for 'Miriam.'
My parents said there was not a 'Miriam' working for them. The man sounded pleasant when he thanked them, then turned and walked toward the corner of the house, which was about two metres away. From there he had to make the long walk down the driveway to the gate.
As he left my mom asked 'Didnt you notice that?' My dad replied 'notice what?' My mom said 'He wasn't standing on the step, he was standing on the ground. Yet he was looking at us straight in the eye! He must be one very tall person." That's impossible!
The 'lights' went on in my dad's head and he rushed outside to find nobody in the driveway, which was impossible, unless he had wings! Looking up and down the street, there was not a single person in sight.
My opinion is that the house was built on a grave and that man was buried there. I may be wrong but that's the only reasonable conclusion I can come to.
I have been absent from this site for a while, and am only catching up now.
Back in those days, Miriam was a common name among domestic workers. I would also assume that is who the tall apparition was looking for.
I can picture the whole setting; you have described it well. Also I can imagine your mom's surprise at someone appearing at the back door, although it was far more common in those days.
Thanks for the interesting account.