the element on my 15 year old GE oven sparked and broke. I ordered a new one to replace it. Once i turned the breaker back on i tested it and it got hot. However in making this repair i noticed on the back of the oven panel the white cotton-looking material that surrounds the wiring looks to be burnt, about the size of a small fist. I dont know if it was caused by the element or just over time. is this a hazard or normal? not interested in a kitchen fire. thanks.