Rearranging the letters of 'Cheerful Christmas light' (Seasonal joy) gives:
A slight elf merits Church.
(by Jim Banholzer) (2017) (pending approval)
Other related anagrams without their own page:
"Algorithm" -> "Logarithm" (by unknown)
"Cheap and cheerful" -> "A chap lunched free!" (by Segura using Anagram Genius) (2003)
"What gift from Santa would you like to see under the tree on Christmas?" -> "True wit, harmony, kindness, calm, rest, good future, seat, health, wife too." (by Aronas Pinchas using Anagram Genius) (2008) (pending approval)
"Merry Christmas and Happy New Year" -> "Starry hype. Many wrap merchandise." (by Mike Mesterton-Gibbons by hand) (2002)