The Brink (2005)

Annoying, abrasive Megan convinces Todd and Bianca to go to an isolated, abandoned home to conduct experiments using Edison's machine that talks to the dead.  Somehow they got the blueprints and were able to build one.

The home is boarded up, but they manage to get in and start to clean up a bit.  No one thinks it's odd that the bathroom has a new shower curtain in it.  Megan decides to take a bath, but the tub is full of sludge and insects.  So she makes one of the others clean it up - booo!  I hate her already.

Years ago a family murdered each other in the home, which has since been empty.  The kids start to use the machine and strange things start happening. When a man with an ax appears out of thin air, they shut it down.  Why do people looking for ghosts always bail when they find them?  Also the group is ill prepared as they bring no extra supplies, such as fuses for the machine in case one blows or doesn't work.

They turn off the machine, it turns itself back on, oh my god there's a big friggin ghost with an ax, oh no there goes my head, Megan had ulterior motives, wish we could all look back and laugh but we're dead.  Damn you, stupid movie.