Battery drain

My battery keeps draining over night on my 91 toyota, i have no alarm system. If i disconnect the pos. lead with the car off i have a good bit of sparking as i remove the lead. What might be drawing current?

Attach a 12V test light between the + cable and the positive terminal of your battery (e.g. bridge the connection with your test light); start removing fuses one at a time - when the test light goes out (for example, when you pull the fuse for the dome light) you will have found the faulty circuit. Then simply test and check all of the loads on that circuit untill you find the problem; good luck.

sounds simple enough! thanks!!!