So, after watching arguably my favortite episode submitted to the series: THE TWO-FACED MAN!, it's opened my mind to what could be the most logical theory concerning what Jesse, Larry and Parker have been witnessing.
Now, you can deny the fact that it's Ursula, that's fine... but it's totally her, let's be honest.
We know she supposedly burned alive in a fire, right? Well, I think her fiancé ( the Two-Faced Man) was in that house with her/tried to get inside to save her, hence why he has "burn marks" on his face, but failed.
Ever since the tragedy of losing his wife, he visits her everyday just before or at midnight to be with her once more.
He asks the three guys if they're dead, because he knows spirits are usually seen around the area, so he was suprised to see actual people, hence why he asked to make sure.
UPDATE: The man in the shed may have been the cause of the fire, but there's so little to go on with that, it's just the two-faced man spoke of him in a distasteful manner.
Regardless, I'm not sure why the guys are getting calls and being tormented, that's probably going to be answered in the future, but for now... I consider the two-faced man and Ursula subject to a tragic lovestory, one that continues... even after death.