I sounds like there may be a leak in the plumbing. If the pump is coming on without someone using water it is going somewhere.
It could be outside in a buried pipe. Do you know where the pipes from the well are located. Are they in the general area of where the water is coming from.
I assume you have looked at all the interior piping for leaks. If you have a turn-off valve AFTER the pressure switch, you can shut it off and see if the pipe still runs. Never shut off the pipe between the pressure switch and the pump when the pump is capable of running. That will tell you if there is a leak between the well and the shutoff valve. Water coming in through the wall implies a leak in the outside piping. If yo have an irrigation system or piping water to some other place on the property it could be there. If the first test does not find it, tell us about other pipes.