I have a situation very much like the one at ImportError: DLL load failed: %1 is not a valid Win32 application, but the answer there isn\'t working for me.
My Python
So I had problems installing vtk under windows (as I use python 3.7 there is no binary available so far just for older python versions pip install vtk is not working)
I did wrote python in my cmd:
Python 3.7.3 on win32
So I now know I have python 3.7.3 runing on a 32 bit.
I then downloaded the correct wheel at VTK‑8.2.0‑cp37‑cp37m‑win32.whl
Next I instlled that wheel:
pip install VTK-8.2.0-cp37-cp37m-win32.whl
Then I tested it and it worked:
python
import vtk