In Your Head

It's been a while, I know. I just had an experience tonight, though, that I have to get down. As a preface, I'll tell you that I believe our house is haunted. Most of the activity is in or around the office downstairs. Keep this in mind...
I had made some Chinese noodles in the microwave. Well, the microwave, which I thought had died (it's been acting like it's wanted to since we bought the place), had actually just tripped the circuit. I called dad to see if that was something that was okay or if we should worry and found out that Eric and Anna were still there. I had thought they had left yesterday, but finding out they leave tomorrow instead, I decided to eat my noodles and head on over to see them one last time before they headed back to Oklahoma. I quickly changed my clothes, shut the upstairs window in the hall, shut the kitchen window, and locked the sliding glass door...lock, bolt, and key. The dogs were jumping up and down, thinking they were going back outside. Then, after locking the front door, I headed on over to my parents'.
I had a nice visit with my brother and his wife...and my other brother and his wife (Steve and Anna came over, too). We finally drew names for Christmas. Finally, feeling a little tired, I decided to say goodbye then head on home.
Here's where the problem is. I get home and lock the car. When I walked in the house, the dogs weren't there waiting for me. That's weird because normally when they hear the beep of the car, they come running downstairs to see me. Instead, it took about two to three calls for them to come downstairs. Well, I went to let them out the sliding door...only to discover the door is unlocked! Lock, bolt, and key...all unlocked. I let the dogs out, then went into the bathroom. I was really freaked out by this point, so after calling Mike, I went back out to the car and called first my parents then 911. They sent two officers right over. They went in the house to look around, but found nothing. They then asked me to come in to be sure nothing had been taken. I went to find Mike's guns...the rifle was still locked. I looked in the handgun case and saw...no gun! I called Mike to ask where he had put it and he told me it was where I had found the case. Mike freaked a bit when I told him. Then, come to find out, there was a layer of foam covering it that I had never seen before. I feel like such an IDIOT! So the officers left after all clear.
I KNOW I locked the back door. I know because the dogs thinking they were going back outside. That's where the ghost may come in...?