oil light on daughter's newly purchased used vehicle

My daughter bought a 93 suzuki grand vitara 2 days ago drove it 20 miles and the oil light came on. When the oil level was checked it had been over filled. I went over this morning drained about a quart which brought it to correct level. Started it up and it drove fine after engined warmed up oil light began to fliker. I stopped checked the oil level, it was fine. Started back up drove it around for 4 or 5 miles with no further oil light flickering. Plan is to have the oil and filter changed, no idea how long it has been since the last one. Any thing else I should do at this point?

You should probably replace the oil pressure sending unit also. Generally it's a simple matter of unscrewing the old one from the block and putting a new one in...

... Oil light coming on is a kill the engine or KILL the engine kind of light, and should be. treated as such, flickering, and false 'ons' can be caused by a blocked passage, or faulty switch. Either way, I wouldn't leave it as is.