The voices are getting louder

I mentioned characters and, perhaps, an actual person from the past speaking to me.

Yesterday, I was upstairs and heard my son calling me from the backyard. He was out there with the dog, so I came running down to see what was wrong. When I made it to the backyard, I found them running in the grass. Both were FINE. So I asked why he'd yelled.
He shrugged. "I didn't."
Oh.

Last night, I was in my bedroom when I heard my daughter call me. (I thought it was her. I am always getting in trouble for going to the wrong room when the other has actually called me.) But this time, they both frowned at me for coming into the wrong room. Neither of them called me. I was sure my youngest was asleep so I gave up.

At 4am, I nearly jumped out of bed when I heard a door slam. I looked at my husband--he'd heard it, too. We looked at each other, then heard the gate at the bottom of the stairs slam shut. We both got out of bed but after I second, I told my husband I was sure it was our older son. (He offered to sneak down and scare the snot out of him but wisely refrained.) When I did not hear any refrigerators opening or water running, I went to check. He was in bed. I checked my daughter's room, and she was in bed. Our youngest never gets out of bed in the middle of the night. Ever. (If he wakes--he cries, calls or just sits there but he does not even get out of his bed in the morning until someone comes to open his door).

But it had to be him. His door was still shut but that would explain the slammed door we'd heard. Sure enough, I went in and found his bed empty.

I went downstairs and found him standing in the dark living room. "I heard Daddy calling me so I came down here," he said, "but now I can't find him."

(I got him back upstairs and we assured him it was a dream. He wasn't completely convinced. He asked his Dad twice more why he'd called him.)

While I was putting him back in bed, I remembered the Bible story where the son woke his father three times, asking why he'd been called. The father finally realized it was God calling his son. My son was, apparently, only called once. And he is three. I don't think God has a message for a three-year-old that can't wait until morning.

Clearly then, there are only two possibilities:
I've invited spirits into the house that want to mess with us (now I know I'm not the only one hearing them) or, the dog has taken up ventriloquism.