Can Evil Spirits Come into Our Lives Through Certain Music and Movies?

Questions about whether evil spirits can come into our lives through openings like certain music and movies and whether putting Bible verses under your pillow to stop nightmares is a legitimate form of spiritual warfare.  

• What do you think about the idea that evil spirits can come into our lives through different openings like certain music and movies?
• My friend said her nightmares stopped after she wrote Bible verses on cards and placed them under her pillow. Is this over-spiritualization, or is this actual spiritual warfare?