Could this be ghosts? do you believe in ghosts?

Okay so im 15 and i didnt really think anything about it till last night, i have around 30 photos pinned up on my wall, and every night for the last five nights one photo has "fallen down" only one a night... there are photos on the wall which i am not in but all of the photos that have "fallen down" i am in, never on my own always with more than just me! but tonight i was sitting on my bed and bottle fell from a 80cm shelve (wasnt sitting on the edge) and bag of bath salts "flew around 20-30cm from a 50 cm shelve. I saw it with my own eyes and decided to ignore it but im starting to freak out now the more i think about it and the later it gets.. I used to freak out at ghosts when i was younger but not recently until now. The main part of my house is over 350 years old, which includes my room so i guess i should only expect this. How do i know if there friendly ghosts or not?