If I was convicted of a non-dangerous felony 2 years ago and completed probation but my fiance owns guns and we live togetherI can i get in trouble?

Yes.  To me more specific, the penalty for possession of a firearm by a felon, can be a 10 year sentence in federal prison and a $250,000 fine. See, 18 U.S.C. 922(g)(1-9)

Possession of a firearm may be either actual or constructive.  The latter has been defined as follows: "Constructive possession exists when a person knowingly has the power and intention at a given time of exercising dominion and control over the object or over the area in which the object is located . . ." See U.S. v. Booth, 111 F.3d 2 (1st Cir. September 1997)

Hope this helps.