okay I saw this movie when I was little mid 1980's don't know what it is. People having sex, guy touches metal head board they both fry. Chick is having a shower burns to death. Something about a lawnmower?
This is likely Slaughter High from 1986. It features a woman scalded to death in a bath, a couple electrocuted to death during intercourse in a metal bed and a guy mowed to death by a riding lawn mower. The entire movie is available here on Youtube.