Same in Poland, note both shown mostly with western culture penetration in 80’s and 90’s, “elfy” is much more used in the context of fantasy elves from Tolkien, D&D etc. Small, faerie like creatures are most often called “wróżki” (lit. “fortune tellers”), while those christmas elves things but not particularly christmas, were very abundant in various roles in Slavic mythology and folklore under the broad name “skrzaty” (similar to the “tonttu” you mentioned i guess but not living only in homes). Slavic mythology don’t really have anything close to tolkien elves or their precursors irish sidhe, closest are nymphs and rusalki similar to nyphs and sirens of the greek myths.

There is also curious dichotomy between words “krasnoludki” and “krasnoludy”, the first being the diminutive form of the second, both meaning “dwarves” but the “krasnoludki” is broad mean for tiny mythical people while “krasnoludy” was only popularised by the first translation of Lord of the Rings and is used nearly exclusively for the fantasy dwarves (people with dwarfism are called “karły” which is also rarily used for fantasy dwarves).