I thought it was leviticus 5:2 that simply says "you shall not touch (them)" - seems to be another verse though - thoughts on this and the title question?
Maybe this is the passage you're thinking of:
(CLV) Lv 11:23
Yet every other swarmer of the flyers which ›has four feet, it is an abomination to you.
(CLV) Lv 11:22
These of them may you eat: the locust, all of its kind, the bald locust, all of its kind, the cricket, all of its kind, and the grasshopper, all of its kind.
(CLV) Lv 11:23
Yet every other swarmer of the flyers which has four feet, it is an abomination to you.
(CLV) Lv 11:24
Also you are defiling yourselves ›with these: Anyone touching i their carcass, he shall be unclean until the evening;
(CLV) Lv 11:25
anyone carrying some of their carcass, he shall rinse his garments, and he will be unclean until the evening.
I don't see any "ceremonial law" mentioned anywhere in the Torah. The law is the law. However there are certain laws that are directed specifically at the Priesthood. This isn't one of them.
I don't consider quarantines, or doing laundry, to be ceremonies.