If you shoot someone, in your home or out of your home, you will be tested for drugs and alcohol. If you are inside your home even if you were drunk, if you had a valid reason for shooting the individual, you would be legally ok.
He came in to "your" house. There is no law against you drinking in someone's house or your own. there are laws that make it illegal to "use a gun while intoxicated" and "using it" will no doubt cause you a problem, even if you were right.
As far as what I said earlier about getting high, I should have prefaced it by saying you shouldn't be here discussing it. The following is Florida law,
"quote"
790.151 Using firearm while under the influence of alcoholic beverages, chemical substances, or controlled substances; penalties.—
(1) As used in ss. 790.151-790.157, to “use a firearm” means to discharge a firearm or to have a firearm readily accessible for immediate discharge.
(2) For the purposes of this section, “readily accessible for immediate discharge” means loaded and in a person’s hand.
(3) It is unlawful and punishable as provided in subsection (4) for any person who is under the influence of alcoholic beverages, any chemical substance set forth in s. 877.111, or any substance controlled under chapter 893, when affected to the extent that his or her normal faculties are impaired, to use a firearm in this state.
(4) Any person who violates subsection (3) commits a misdemeanor of the second degree, punishable as provided in s. 775.082 or s. 775.083.
(5) This section does not apply to persons exercising lawful self-defense or defense of one’s property. "end quote"
http://www.leg.state.fl.us/statutes...ng=&URL=0700-0799/0790/Sections/0790.151.html
When it says to the extent your normal faculties are impaired, you can be pretty sure that anything they find in your test will mean you were impaired, unless you were sitting on your couch and someone broke in, and you had to shoot them, in which case you would be fine, according to the written law.