Okay, I don't really have the best answer, but sence your family has had contact in the paranormal also, I think you are opening it with a special power that all humans have, a phycic power that can be relesed through mysterious resons. Some can be love, stress, worry, recent death, big things. Even some dreams can release it. And these visions, they aren't helping your problum.I think you must have a strong sence in paranormal and the spirits probly find you like a family figure. Wheithr it be parental, sibling, grandparent,ect. I think that's the problum. That's what ghosts want: a family. You have kids, so it is probly parental. You can't close a portal, I dont think, but maybe you can, I dont know. If you can, do, if you can't, try to deal with it. If the spirits are causing big drastic problums, get out of there FAST!!! Spirits arent the only thngs that can come after portals, demons can too. You wont get a demon if your house is clean, you aren't on drugs, you arent an excesive drinker, and/or you have a christian symbol of some sort in your house. This doesnt always work, though, but i think youll be fine.