Anytime you hear the “equity” argument being raised on Beacon Hill, hang on to your wallet.

And so it is with a Senate-backed proposal to force satellite TV subscribers to pay a 5 percent tax on their DirectTV or Dish Network bills.

The proposed new tax made its way into the Senate version of the fiscal 2010 state budget. But since it’s not in the House version, it now becomes an issue for the budget conference committee to wrestle with.

Cable TV companies have argued that since they have to charge their customers a 5 percent “franchise” fee - which goes to cities and towns presumably to reimburse them for the cost of having those cables run through their communities - that it’s only fair to have a similar tax put on customers of their rivals in the TV business.

Now add to this equation the insatiable lust of state lawmakers to tax anything in sight so as not to have to cut any of their favorite programs and, well, you have a perfect scenario for yet another money grab.

Subscribers’ only hope now is that House conferees will see the absurdity in it all. After all, satellite TV is beamed down from something like 22,000 miles away in space, which means the Senate is at long last proposing to tax - yes, air.