Leaky shower head has hole in the hose. Placed on stall floor. Few weeks later and I now hear running water behind stall. Faucet pipes and arm are warm to the touch with no water running. Live in Mobile home set on ground. No way to see underneath.Help Please Don't know what to do or try.

Leaky shower head has hole in the hose. We have to get in the same page with terms. Your shower heads's on a hose coming out of the wall and the hose has a hole in it. Is that correct?
Placed on stall floor. You placed the hose on the shower floor. Right so far?

few weeks later and I now hear running water behind stall. After placing the hose on the floor you now hear a leak. Right?
Faucet pipes and arm are warm to the touch with no water running The supply to the shower valve and the shower are are warm without being turned on. Is all this what you want me to base a solution on? This running water that you hear, Do you see any sign of a flood? Is water pouring out from the bottom of your trailer? If I'm incorrect in repeating what you've posted please post back and correct me. Back to you. N Tom

All is correct. There appears not to be any flooding, but no way to look under trailer.

All is correct. There appears not to be any flooding, but no way to look under trailer. sorry. The running water just occurred on Sunday, the shower head when not in use has been on floor for few weeks.I'm not sure if it matters or helps.

Is there any way to gain accest to the backside of the shower valve? May have to cut a hole in the wall on backside if possible. This will give you access to see where the water is going.

Is there any way to gain accest to the backside of the shower valve? May have to cut a hole in the wall on backside if possible. This will give you access to see where the water is going.

Only if I break through the wall. Landlord won't like it but he stated any repairs its all on me.

You'll have to open the wall to get to it then (easier to fix dry wall then fiber glass)... just make a square opening from stud to stud that way it will be easier to patch up. It sounds like you have a leak in the pipe from shower valve to shower head if I'm understanding you correctly, you'll just need to replace that pipe.