A Spirit(father who ped)that's bothering me now?PLEASE CHIME IN!?

My best friend has been experiencing paranormal things going on for the past 3 yrs on/off and recently got worse/continuous .lights on/off while in the shower,hiding keys/tv remote,cold cold presents touching her hair,back of her neck,..well long story short we finally get an answer and it's her father who ped 23 yrs ago.well he ped Oct.21(by a drunk driver) and it's been everyday since the 18-19th.She tried to tell him to stop but,she's too scared while saying it.I know he was sad/not happy before he ped from what her mother has told her and she feels it cause she would just start crying on occasion out of the blue.I want to know if he is feeding(energy)off all of this or he trying to communicate,send her a message or tell her something?Would telling him to stop in a yelling annoyed manner work make it worse?Why won't he stop?She's a kindergarten teacher and she's lost ALOT of sleep the past week and I hate seeing her like this:(