You are a nurse and you got a small job, which is to take care of an old man for just one night, the house where you are working was recently purchased, in fact it's their first day in there. They purchased the house for a really good price, but there was a catch... the house doesn't have electricity, the wires are very old and need to be replaced.
The individual that bought the house has been working on some kind of hand crank generators for many months and now it's a great opportunity to test them out, he set 4 devices around the house, that's all you have to rely for lighting during the night.
These devices had been pretty stable during the development, but there is something in the house that's making them unstable. No matter what, don't let them run out of power, there is something hiding in the darkness!