I would like to find blank cells that contain a single space, then highlight all cells which have a single space.

Option Explicit

Sub blankWithSpace()
Dim rng As Variant
For Each rng In ActiveSheet.UsedRange
If rng.Value = " " Then
rng.Style = "Note"
End If
Next rng
End Sub

Here is the message I get when attempting to run:

This is the expectation:

Before running the macro
After running the macro