How do i stop this paranormal activity?

Ok, heres the thing, a month or two ago, i heard a loud bang, it was so loud that i picked the house phone up to call 911. Then it apperaed to be nobody but my fiancee and i both were so scared. A few days later something played a few strings on my fiancees bass guitar and it fell over when we woke up to turn on the light, we prayed for it to go away, and it did. A month later my friend brought up a ouji board and said she'd like to play it, adn i for some reason considered it, it was never here.. So i did random research online about them.. Then last night my friend stayed over and said she heard like 5 knocks on the bedroom door, adn this thing came in and played the bass guitar for 10 minutes!! She said she didn't look and didn't see anything. i'm so confused what to think, or what to do... so i reaserched some more, came across this online fake game ouija board to see what it was like, FAKE IT MOVED THE POINTER AND DIDNT ANSWER ONE CORECT QUESTION ABOUT ME, THEY ALL REFUSED HAHA. but i was hoping to come across what is going on, it ahsnt seemed to try to harm us, she said she also heard like a faint normal radio.. maybe she was dreaming cause we brought upt the first instances before she went to bed.. I didn't wake up to hear it, which i think i may have? please help, don't be rude please, i'm just so confused, never had this stuff before