The decorating tended to be evergreen tree branches and red berries. Im not sure light came on to it but you could be right.
Christians hijacked the winter solstice so they could say "join our club, we have great parties at mid winter"
I recall the Nimrod campers had three evergreen trees as their logo.
History teaches that Nimrod's symbol was the evergreen tree in symbol of everlasting life.
If I remember, the light was from the placing of candles on the branches, and even light from festive bonfires.
I think, even with holiday dress we find candles lit in a Scandinavian country.
Might sound nit-picky but it was the 'so-called Christians' who hijacked......
Jesus nor his apostles celebrated the solstice.
As a matter of Scripture, the only thing Jesus said to remember was his date day of his Spring death.