The aforementioned practice is unfortunately very common in different parts of the world. It is based on a narration which has been classified as a fabrication by the masters of Hadith. Some of them are: Hafiz Sakhawi, Hafiz Ibnud-Dayba’, Hafiz Ibn Tahir al-Fatani, Shaykh Abdul Fattah Abu Ghuddah and others. (rahimahumullah) (References for all of the above: Al-Maqasid al-Hasanah pg.450, Tamyiz al-Tayyibi min al-khabith pg.171-2, Tazkirat al-Mawdhu’at pg.34, footnotes on Al-Masnu’ of Mulla Ali Qari pg.169)

 Although some predecessors have experienced relief from eye infections after habitually practicing the above, to consider such an action to be wajib, sunnat or as part of din is incorrect and will then render it a bid’ah (innovation).(Bawadirun-Nawadir)

https://hadithanswers.com/kissing-fingers-upon-hearing-shahadatain/