Untested Safety tester it's not exactly an oxymoron but it's certainly moron adjacent.

Over to aBay who is certainly more on than she is off.....

This vintage Clare V.152 electrical safety tester, made in Worthing, England, is a powerful tool for any DIY enthusiast or workshop. With its reliable brand and quality craftsmanship, it is sure to meet all your electrical safety needs. Ideal for testing all kinds of electrical equipment, this tool is a must-have for anyone who values safety and efficiency.