Related for Beitzah 4:4
אֵין פּוֹתְחִין אֶת הַנֵּר, מִפְּנֵי שֶׁהוּא עוֹשֶׂה כְלִי. וְאֵין עוֹשִׂין פֶּחָמִין בְּיוֹם טוֹב, וְאֵין חוֹתְכִין אֶת הַפְּתִילָה לִשְׁנַיִם. רַבִּי יְהוּדָה אוֹמֵר, חוֹתְכָהּ בָּאוּר לִשְׁתֵּי נֵרוֹת:
One may not "open" a lamp (on yom tov) [by taking one of the potter's "eggs" and sticking his fist in it to hollow out (the bowl for) a lamp], for he thereby makes a vessel. And one may not make charcoals on yom tov, [these, too, being "vessels" for goldsmiths], and a wick may not be cut in two. [A wick, too, is a "vessel" for kindling, requiring preparation. It may not be cut in two, for this is amending a vessel. (But it is permitted to "mash" it in one's hand.)] R. Yehudah says: He may cut it by fire into two lamps. [He places the two heads of the wicks in the mouths of two lamps which he must light at the same time, and lights it in the middle. For now he does not give the impression of fashioning something, but of lighting (a lamp). The halachah is in accordance with R. Yehudah.]