On Saturday, December 19, 2020 at 12:08:39 PM UTC-6, wrote:

I never have anyone in the shop while I'm working. Well, no one would
want to. ;-) The cats aren't allowed downstairs and SWMBO wouldn't
think of it.

I set up a door bell in my shop with a wireless remote button sitting on the kitchen counter top. My wife rings the door bell if she wants my attention. We understand that bursting into the shop unannounced is dangerous. Its not perfect, but it works most of the time.

Bob