What should I do with a rolled-up piece of hair and a paper with my phone number written backward that I found on my path?

Whoever finds a magic (sihr) should undo it and bury it, just as the Messenger of Allah, peace and blessings be upon him, did with the magic that was cast upon him, for he commanded it to be buried. This hadith indicates the permissibility of undoing magic and burying it to nullify its effect. Aisha asked the Prophet, peace and blessings be upon him: "Did you take it out?" He said: "No, as for me, Allah has cured and healed me, and I feared that I might stir up evil among the people because of it." And he commanded it to be buried. The Prophet, peace and blessings be upon him, sufficed with burying it without undoing it for fear of fitna (discord/temptation). The secret behind this may be so that people would not see it and learn it. As for the narration "Should you not have burned it?" it is anomalous (shadhdhah). It is recommended to maintain the morning and evening remembrances (adhkar) to ward off and remove magic.