"Colbyt" wrote:

The metal can is most likely just the junction box for the heater.

All of these that I have ever seen are surface mounted units. Yours may have
a recessed junction box as mentioned above. You should have drywall under
what you remove.

It is NOT surface mounted. I removed the old heater. Most of the
heater was inside the round metal can which is just under 13 inches
in diameter and about 7.75 inches deep. The bottom of the can is
flush with the ceiling drywall. With the heater removed, there is a
big, deep, hole in the ceiling. The hole is the size of a large
cake or a hatbox.
--
I don't understand why they make gourmet cat foods. I have
known many cats in my life and none of them were gourmets.
They were all gourmands!