I remember that my best friend when I was little (in Boston) used to light candles on their tree (or her parents did). It’s just a short glimpse of a memory, so I don’t know how long they were lit or anything, but they were at least for a short time. I don’t know if her ethnicity is German (if it is, it’s at least a couple generations removed).
I think the trick is that the tree is very very freshly cut since Germanic traditions dictate you dont get a tree until Christmas eve and it is only lit for a night or 2. I wouldnt recommend that on a tree that was a week old or older.
Haapy Christmas everyone!