I have a 1980 Mobil Home with 3 fluorescent light fixtures in the ceiling, (2 - 4 foot and a 2 foot) there are no boxes in the ceiling, the wiring is thru a hole in the ceiling and the connection is made in the fluorescent case with wire nuts. I want to replace them with newer round fluorescent fixtures and boxes, the fixtures say ď if power supply wires are within 3 inches of ballast use wire suitable for at least 90 C. (And of course they would be, the ballast is in the center of the fixture where it is mounted to the box. I have contacted Diamond where I purchased the fixtures and they know nothing about this, never heard of it, I showed them the info on the installation directions and they said this was all new to them. They donít know how to tell wire heat ratings. I contacted several electricians to find out if my wiring was proper, I got answers from I donít know how to tell, to as long as my house wasnít from the 40ís I should be good to go. The American Fluorescent Corporation said I should be fine. I just read about the difference between NM and NM-B. I have NM wiring. Will I be safe to install these lights and do I need to cut the paper away from the insulation when I install the boxes, this is not done on the other lights installed in boxes on the ceiling.