I set my control machine to one temperature and it goes to another temperature

Some nights I think there are ghosts in my home. I do live in an older farmcabin and there have been particular times where I have been scared out of my wits because of things I have experienced. There was this one time where I put my pop cup in the residing room and I set it down on the pop table and 5 minutes later my pop cup was in my study room sink. It was the weirdest thing because the residing room got definitely frosty and when I went to go look for my pop cup I could not find it. There was no one in my house, it was just me. A recent incident that I have experienced is that the temperature that I set my control machine for is not that temperature. At first I thought it was the ghost playing a trick on me again however what I found out was that my control machine was not properly calibrated. When a control machine is not properly calibrated it can be super frustrating because even after a control machine ends up being calibrated they lose their calibration again shortly after the heating and cooling serviceman works on it, then digital control units I have learned never lose calibration and they are extremely accurate! Unfortunately I have an older mercury type control machine and this can happen. I have heard that digital control units can save me up to 30% on utility costs due to the accuracy of them! Now I know that this time it was not the ghost in my cabin it was just my control unit. I think I am going to have to replace to a digital control unit.

furnace/heater tune-up