Assalaamu ‘alaykum Mufti Sahib.
Can a kaafir be possessed by a jinn? Are there reports from our kitaabs that mentions any kuffaar having being possessed?
Yes it is possible for them to be possessed.
Jinns like teasing vulnerable people. They avoid strong, courageous, assertive persons.
So if a non Muslim was a soft, weak person the jinn would attempt to harass them. But if they were positive and they ignored everything and got on with their lives, jinns would be frustrated and flee.