Took one 5mg Lexapro (escitalopram) on Monday night and then decided not to take again. Is it safe to drink alcohol tonight approx 96 hours later? No other meds.

Don't stop like that. It strikes me that drinking is less of a concern related to your medicine than it is regarding your anxiety. Alcohol can be tricky to predict if you are not feeling well emotionally, so I would consider that. Since you were only taking your Lexapro (escitalopram) for one day, you probably did not have a bad reaction. But for the future, stopping antidepressants suddenly can make you feel terrible. Be careful.
Yes. I wonder why you changed your mind? In people with anxiety disorders, alcohol sometimes increases their anxiety. I hope that even if you prefer not to take medications, you can see a therapist to help you deal with your anxiety. Take care.