Motorola E815 / E816 Hollywood

I love the h500 headset, it's nice and light. However, I find that when I use it in my home, I get static/crackling . When I am out of my home, it is crystal clear! Is there a reason or adjustment that I need to make? Perhaps the wireless internet is interfering???? Also, it sounds (in my home) a bit muffled. Any thoughts...