I found this forum when I did an internet search on "chirping" GFI. I read it but didn't really see what I was trying to figure out. I am a glass artist and use many tools that run on water and electricity. The past couple of times I have used my wet belt sander I heard an occasional chirping noise. I thought it was coming from another part of the studio - it sounds like the noise one hears when a battery in a smoke detector is failing, only the duration is shorter. So, between a chirp and a beep is the best I can describe it. It never occurred to me that it could be the GFI receptacle. This morning I went to use the WBS and was straightening the belts and the top cylinder felt warm to the touch. I felt the motor and it was cool. The studio was at 100 deg because I had a kiln running all night but don't think this could account for the warmth of the cylinder. I went ahead and used it and the chirp/beep is still occurring and I thought about the two things and, at the moment, I am thinking I am fortunate I haven't electrocuted myself. If anyone has any insight to offer on what is going on I would greatly appreciate it. Thanks!