Did you search ["time delay" toggle switch]? I have not seen one that does not have the optional constant on position. You can do it with a timer attached to another junction box somewhere, maybe at the fan. You could consider a switch with a constant-on position and do a mechanical modification of the switch or switch plate that locks that position out. (Just get an identical face plate, cut a strip of plastic from it and glue it onto the mounted face plate to limit switch movement.

Another possibility is an occupancy sensor. Some of them have an adjustable delay built in.

Yes, I did.

I suppose a manual on/auto off occupancy sensor would do the trick, though they look rather high-tech for our house. Thanks for the suggestion.

Lutron makes a nice little timer that you can preset for the off time. One tap turns it on and it turns itself off after x minutes. Two taps turns it on continuously, another tap shuts it off.

Unfortunately it's part of their Maestro series which means it's a Decora type switch. Does work well.

Requiring "two taps" would seem to make it much less likely to be turned on continuously. I wonder if they did any studies to compare that and consumer preferences to "push and hold". A pilot light that comes on with continuous would be desirable for me, perhaps even a little sonic alert.

Requiring "two taps" would seem to make it much less likely to be turned on continuously. I wonder if they did any studies to compare that and consumer preferences to "push and hold". A pilot light that comes on with continuous would be desirable for me, perhaps even a little sonic alert.

Double clicking often gives the wrong operation twice rather than the proper one twice. The human factors guys are on the side of press and hold.