Keep in mind that there may be substantial variation in the amount of viral shedding for infected people (there are superspreaders, presumably there are also subspreaders), as well as in the susceptibility of people to the virus (presumably there is some cross-immunity for people who have had a coronavirus-type common cold recently, for example.) So the transmission rate among household members can’t necessarily be estimated from the per-contact rate assuming each contact is an independent chance of transmission.
Keep in mind that there may be substantial variation in the amount of viral shedding for infected people (there are superspreaders, presumably there are also subspreaders), as well as in the susceptibility of people to the virus (presumably there is some cross-immunity for people who have had a coronavirus-type common cold recently, for example.) So the transmission rate among household members can’t necessarily be estimated from the per-contact rate assuming each contact is an independent chance of transmission.