My first earnings short-squeeze idea is electronic instrument and controls player Plexus (PLXS - Get Report), which is set to report its numbers on Wednesday after the close. Wall Street analysts, on average, expect Plexus to report earnings of 48 cents per share on revenue of $527.80 million.If you're looking for a stock that's been uptrending very strong ahead of its quarter, then take a strong look at shares of Plexus. This stock has ramped up big from its October low of $21.06 to its current price of just over $32.50 a share. This stock is up over 19% so far in 2012, and it now is trading right below some key breakout levels. The current short interest as a percentage of the float for Plexus is 5%. That means that out of the 34.21 million shares in the tradable float, 1.72 million shares are sold short by the bears. This isn't a huge short interest, but the float is small so it's more than enough to spark a big short-squeeze if the bulls get the news they're looking for. From a technical standpoint, PLXS is currently trading below above both its 50-day and 200-day moving averages, which is bullish. The strong run in this stock during the last few months has now put it in range to trigger a big breakout trade. f you're bullish on PLXS, I would look to get long after they report their results if the stock trades back above some near-term overhead resistance at $33.79 with volume, and then above $34 to $35.36 a share. Look for volume that's tracking in close to or above its three-month average of 308,841 shares. If those levels get taken out post-earnings with volume, then look for PLXS to trade back toward $38 to $39 a share. I would only get short or avoid any long trades in PLXS if after they have released their results the stock fails to takes out $33.79 with volume. If that level holds as stiff resistance and you get short, I would then add to any positions if it takes out its 200-day moving average of $29.58 with volume. Target a drop back toward its 50-day moving average of $27.37, or possibly lower if the bears destroy this stock post-earnings.