To light up houses in pre-Xmas time was not usual in Germany until this usage was brought into towns with US garrisons.
Now you see a lot of genuine German houses decorated with light chains, Santa Clauses in the windows &c.
It is still considered indecent to start the decorations before Eternity Sunday (or Deads' Sunday), the last Sunday of the Church Year.
Here in my native town the lights were lit last Sunday, the 1st Advent Sunday.

Wilfried