gives a nuance of 'it may' to sentences, implying low probability. It is less certain than でしょう
日本に引っ越すかもしれない。 I may move to japan.
パーティーには行かないかもしれない。 I might not go to the party.
Just add it directly tonoun＋ , don't add a copula!
病気かもしれない I might be sick....
かも
Often abbreviated to just かも. Meaning is same, but as with all abbreviations it's very casual.
明日は雨かも It might rain tomorrow.
漢字はむずかしいかも Kanji may be hard.