What a scarey morning NPR

The house next door to us, which is actually very close to the end of their property line so it's rather close to our house, has been vanant for quite some time. It's a small house - an old lady lived there till my landlord put her in the nursing home last year. Since the house hasn't been used much at all, the door swelled and we are waiting for my landlord to let us know if it's OK to do work on the frame. So the door has been open a crack for the most part, but it's incredably hard to open regardless. This morning at 6 it was like it always was. Then at 7 I notice the door is WIDE open. I call DH since that's the time he's switching jobs, and he was able to run home. He made sure no one was in the house (carrying a hammer so you can imagine how my heart was beating OUT of my chest)... no one was in there. The TV and such was still there. He closed the door again, but he said that there's no way the door couldv'e opened on it's own. So someone was def there. He told me to keep an eye on it...if I see it open again I then call the cops.
I don't need some homeless person living in a vacant house (which is now for sale) that is sooo close to mine. I'm alone from 3am till about 6pm each day.
My question is now, do you think the cops would be able to some way or another make the door close? Should my DH just go ahead and sand the frame down tonight just so we know no one can get in..? My landlord is still on vacation...so I'm at a loss getting her permission first.
Our backdoor is really our side door, so when I let the dog out, we are right next to that house. If anyone comes out of that house while the dog is out, he will NOT come in. So if it is in fact a homeless person, I can't help but think that if he gets scared with the dog barking that he comes over to us. Just what would I do? Ahh... my DH told me that it's fine now...no one is there. And since it's later in the morn, he doesn't think that same person will come back...considering how close everyone is in this neighborhood. But it still urkes me. Just needed to get that out... Just freaks me out.

Re: What a scarey morning NPR

I would be freaked out also. What you can do is have DH try to lock the door. Get something that he can padlock from the outside. I know your landlord wouldn't want a squatter in there either so I doubt they would object. I can tell you the person probably isn't there now but they probably went in during the night when everyone is sleeping