Humidity rising in basement
I'm looking for advice on how to find what may be a hidden water leak.
Over the last week, our temperature and humidity sensor has shown an increase in humidity in our fully finished basement. It went from averaging about 55% to 60%. Not a big jump, I know, but we are serious about keeping it below 60% to keep mold and mildew down, and it's very rare for it to go that high.
Additionaly, my parter (who is senstive to mold and mildew) is starting to react when she's in the basement. This is where our master bedroom is. It's also where our laundry is. There is also a full bathroom, but we only use the toilet and sink (never the shower or bath). With all this plumbing, and it being behind drywall, I'm worried we have a hidden leak.
The weather here has been dry and sunny, with no precipitation, so I don't think it is coming from outside.
In the mean time, we are running a dehumidifier. It initially took the hummidty level down to about 45%, but it comes back up when we don't run the dehumidifier.
Any suggetions on how we might find a leak, without cutting drywall?
EDIT: There is no AC in use, and the temp in the basement is pretty steady around 60F.