YOU SAID:

I think there is a ghost behind me

INTO JAPANESE

私は私の後ろに幽霊があると思う

BACK INTO ENGLISH

I think in the back of my ghosts

INTO JAPANESE

私の幽霊の後ろにだと思う

BACK INTO ENGLISH

I think behind the ghost of me

INTO JAPANESE

ぼくの幽霊の背後にあると思う

BACK INTO ENGLISH

I think behind the ghost of me