My breaker box has one extra 20 amp tandom breaker, but the ground and neutral lugs are full. Can I put two wires in each lug or is there a better way to do this? Thanks

anyone?

Still a problem? If so, is this a 120 volt spa (plugs in)? When you say extra breaker, is this an empty space or unused breaker? The ground and neutral lugs that have wires, are they on the breaker or in the panel? Here's what you should have for '94 Sovereign 120V: 20 Amp dedicated 120V line. GFCI breaker in panel (properly connected). 12-3 wire direct to spa receptical. HotSpring has replacement receptical with integrated weather-proof cover and GFCI plug for your spa if it hasn't been updated already. check http://www.hotspring.com for wiring details, go to "customer corner" and select "owners manual and pre-delivery instructions" any pre delivery booklet is fine as the 120V wiring hasn't changed since the '80's. Look at wiring for the Sovereign (model I, not model II), Prodigy (model H) or Jetsetter (model J) and the 120V wiring is correct for your '94 Sovereign.

Yes 120v. I have one 20a breaker in the breaker box that is unused. The ground and nuetral is mounted in the breaker box.My spa also has the gfci plug on it.

Your spa is 20amp 110v. It cannot be reconfigured.

What it sounds like your asking is whether you can "piggy-back" another set of wires into a breaker that's all ready serving a circuit.

If so, you're asking for trouble. Look to see if your panel accepts split breakers at the bottom of the box. These allow for more room. Best to check with an electrician if this is what you're after.