LAWRENCEVILLE, N.J. - Rob Becker of George Mason University has been named the Colonial Athletic Association Wrestler of the Week, and Don Fisch of Rider University has been named the CAA Rookie of the Week, for all competition November 25-December 8.    Becker, a senior 141 pounder from Mickleton, NJ (Clearview Regional), won his weight class at the prestigious Cliff Keen La Vegas Invitational, winning all six of his bouts.    Becker, currently ranked ninth in the nation by Amateur Wrestling News and 14th by InterMat, was unseeded in the tournament and defeated the seventh ranked Jeff Ratliff of Ohio State (15-11), the 12th ranked Joe Clark of West Virginia (7-5 o.t.) and the 18th ranked Max Meltzer of Harvard (4-2).  Becker improves to 10-1 on the season.    Fisch, a freshman 133 from Williamstown, NJ (Delsea Regional), won both of his bouts at the Sheridan Duals, including a 7-1 decision over the 12th ranked wrestler in the nation, Matt Ciasulli of Lehigh.  At Lock Haven's Mat Town USA tournament, Fisch placed third, defeating Chris Lape of Slippery Rock 4-2 in the battle for third place.  Fisch lost to the sixth seed, Matt Easter of Cornell, 7-3 in the quarterfinals, before winning four bouts in the consolations, including two falls and a major decision.      Currently ranked 16th in the nation by AWN and 20th by InterMat, Fisch wins the CAA Rookie of the Week award for the second time this season, and improved to 11-2 overall.