2006 F350 membrane horn switch
 

I am new to the forum and would appreciate some help .... I would like to locate a replacment part / part number for the horn activation membrane that sits under the cover of the steering wheel (sits on top of the air bag).
I was traveling over the Rockies last week and my horn started blowing non-stop after passing the 10,500' elevation level. I had to disconnect by pulling a fuse. Now that I am back at 1200' elevation is seems ok but is way too sensitive.
Any feedback would be appreciated.
Thanks David A.